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doughairfield
07-14-2009, 01:17 PM
Ok, having something strange going on. I can't seem to get my TR4 to start, here is the behavior.

About a week ago I went out to start it and turned the key and it made a few turns and then died, so I was thinking that the battery was dead. I went to get the jumper cables and decided to give it one more try before I hooked them up, started right up. Drove it a few places, would start up. Then stalled on a hill, turned the key, only got that one click sound. Rolled it off and drove straight to the parts store where they tested the battery and said it was dead, and sold me a new one. Started right up no problem with new battery and has for a week.

Today, drove to work, went out at lunch, nothing, just the one click of I guess the solenoid when I turn the key. I rolled it off, ran fine to get lunch. Rolled it off again after lunch, but as I got back to the office I noticed it was missing badly, running rough AND the engine temp was way down, near 30. Barely got it back in the deck and turned it off. Turned the key, nothing.

I'm skeptical that the alternator is bad as up until an hour ago, was running, and I'd be surprised if it was just off the battery. I have not tried to roll it off again, to see if it will start, but maybe starter or solenoid is bad?

DrEntropy
07-14-2009, 01:26 PM
Sounds like some diagnostics are in order.

A V.O.M. is really necessary here.

Charge the battery, get it running and test the alternator output. Battery voltage should be 12.5V with nothing connected. Running, the voltage at the battery terminals SHOULD be around 13.5~14V. Lower than that indicates a charging problem. I wouldn't jump at the starter or solenoid until the alternator is checked from what you describe. Sounds like it WAS running off the battery only.

tdskip
07-14-2009, 01:27 PM
Well - they will run off the battery for longer than you might think. If the alternator isn't charging the battery it will run for a while and then die.

Have you tried charging the battery and seeing it starts again?

If the alternator is good and charging properly - and you'll need to get it running to see if that is the case.

I don't believe that starter or starter solenoid will impact how the car runs once it is in fact running.

Keep us posted Doug.


DARN - BEATEN BY DOC YET AGAIN....

DrEntropy
07-14-2009, 01:29 PM
And I ain't even on line!! :wink:

TR3driver
07-14-2009, 01:32 PM
Sure sounds like charging system problems to me. You can go an amazing amount of time on just the battery (or on an alternator that works a little bit). The running rough and temp gauge way down sound like symptoms of very low system voltage, meaning the battery had finally run down that far.

My suggestion would be to get something so you can monitor the charging system; either install a voltmeter or rewire your alternator installation so the original ammeter is functional. Or even just a hand-held DMM (under $10 from HF) will do for now (but I'd still want a dash gauge for the future).

Also check that all your battery cable connections are clean and tight. I had a somewhat similar problem on a Chevy once that turned out to be the connection from the frame to the engine was loose. It would spot-weld and work for a bit after starting the engine, then vibration would break it loose and the alternator would no longer charge the battery.

DNK
07-14-2009, 01:53 PM
Bad battery connection

doughairfield
07-14-2009, 01:58 PM
First, thanks everyone so much for the speedy write ins. I'm kind of stuck at work right now, a bad place to be stuck.

I failed to mention, that I did also replace the Pos battery terminal cable when I switched out the battery because the old one was looking pretty ragged and frayed. I'll take it off and make sure it's making a good connection to the frame as well.

I'm going to get a friend to charge it up via jumper cables for a while and see if it will turn over. I wish I had a Multimeter here, but don't of course.

DrEntropy
07-14-2009, 02:24 PM
Pull the negative terminal off the battery before ya hook up the jumper cables. :wink:

doughairfield
07-14-2009, 02:26 PM
I've not heard of that before, granted this is the first time I have tried to jump it/charge it. Can you explain why?

DrEntropy
07-14-2009, 02:34 PM
If there *IS* an issue with the alternator, charging system or other drain on it, you'll be spinnin' yer wheels (so-to-speak) tryin' to charge it while it's all connected. Give it 15 minutes at an RPM just above idle on the other vehicle.

...and don't dawdle onna way home if it lights off. :wink:

doughairfield
07-14-2009, 02:54 PM
Ah, I see, what you're saying. And I did have to run the head lights the last few days. Can't believe it would run as much as it did on the battery alone.

DanB
07-14-2009, 03:39 PM
Check your ground first. Bad grounds are the root of many problems on these cars.

Dan B
S. Chas. WV
66 TR4A IRS EFI
80 TR7 DHC

doughairfield
07-14-2009, 03:46 PM
I just spent about 15 minutes with the battery connected via jumpers to a friends car. Turned the key and it started right up, so I am thinking the alternator is not charging. Plus and please correct me here, the ammeter in the dash should show ~12 charging. The needle is hanging to the right on the negative side. Does that indicate a charging problem, I'm guessing yes. Are there further tests I could perform or just go ahead and change out the alternator?

doughairfield
07-14-2009, 03:46 PM
Ok, so probably a dumb question, but the ground, being the positive, just goes straight to the body/frame. Do you have a suggestion as to how to test that?

TR3driver
07-14-2009, 04:04 PM
Hmm, positive ground is original; but the original generator was not an alternator and positive ground alternators are scarce as hen's teeth. Has your car been modified with an alternator (AC generator) or not? I ask because some people doing the alternator modification hook it directly to the battery such that the ammeter no longer indicates whether it is charging or not.

If it's original, then the ammeter hanging to the left all the time does indicate a charging problem. Normally after starting it should swing sharply to the right "+" side, with the engine above idle (1500 rpm) then slowly settle towards the middle (with the headlights off). Very slightly to the left with the headlights on or with the engine idling is normal.

However, not charging is not necessarily the generator's fault. It is controlled by the control box on the firewall, so a problem with the control box or it's wiring could also be the issue.

What is the red light doing?

doughairfield
07-14-2009, 09:32 PM
The red light has not turned on at all through the whole ordeal.

I have looked at the repair manual, but honestly, it's a bit beyond my skill at this point. I did read about the voltage regulator and the control box, so I am charging the battery now and will try and trouble shoot tomorrow.

As far as the alternator and if it's original, I'm not sure of that either. I'm going to try and contact the person that had it before me to see if they have any info on it's history.

For the short time I've had it, the ammeter has never gone to the left side, which is labeled +, I assume the charging side. And when I drove it tonight, I turned the lights on and it went far to the right, the negative side and stayed there.

So could be, Alternator, or Voltage Regulator at this point?
Anyone have a suggestion for how to narrow it down?

tdskip
07-14-2009, 09:41 PM
Doug - do you have a digital camera handy? Pictures always help....

doughairfield
07-14-2009, 09:44 PM
sure, should I take a pic of the generator(or maybe it's an alternator)? I do know for a fact, everything is still positive ground. I'll go snap pics now if you let me know what to take a picture of.

Andrew Mace
07-14-2009, 09:58 PM
Does it look more like https://www.ytmag.com/store/parts/pics/wm_GLU0001.jpg (generator)


or more like https://www.nationsautoelectric.com/images/20-102-8.jpg (alternator)?

doughairfield
07-14-2009, 10:02 PM
ok, I went ahead and attached some pics. So is this an alternator or generator?

doughairfield
07-14-2009, 10:03 PM
front view

doughairfield
07-14-2009, 10:03 PM
Voltage regulator

doughairfield
07-14-2009, 10:05 PM
Ah, thanks for the pic, it's definitely a generator.

doughairfield
07-14-2009, 10:13 PM
I did fail to mention this earlier, maybe it will help, but when I was driving home, I noticed that if I kept the engine above 4000 RPM it would not start to cut out, I'm assuming due to low voltage from the generator. Again, maybe that will jar someone's memory.

doughairfield
07-15-2009, 10:07 AM
So at this point, I'm feeling like the generator is on it's way out as spinning it up pretty high seems to produce sufficient power to run the car. Would replacing the brushes be the next step? I know the generator is at least 20 years old and has had no maintenance in that time. Should I just go ahead and replace the whole thing?

I'm going to try to test out why the red ignition light has failed to come on by disconnecting the brown/yellow wire from the generator and touching it to ground per the suggestion on the VTR site.

TR3driver
07-15-2009, 10:34 AM
Hard to tell for certain, but I don't see enough wires in your shot of the regulator. There should be 6 wires and I only see 5. The D terminal gets two wires, one of which goes to the dash lamp and the other to the generator. The E terminal should have a ground wire, which goes both to the body nearby and to the instrument panel in the dash.

IMO you should do some more tests before removing the generator. For example, dirty contacts in the VR relay (combined with a burned out red light) can cause just the symptoms you are seeing. Here is (https://www.sterlingbritishmotoringsociety.org/files/Lucas_Generator_and_Control_Box_Tests.pdf) a PDF file with suitable tests. Note that even a cheap DMM (https://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92020) makes a adequate substitute for the prescribed moving coil voltmeter.

doughairfield
07-15-2009, 10:50 AM
Thanks so much. I will get on that tonight when I get home tonight. I have the TR4 repair manual and have started reading the info on the regulator.

I also got a DMM today. To see if things are working properly, I should see ~13 volts across the battery terminals with the engine running and the generator charging?

Stinger
07-15-2009, 11:27 AM
If everything else checks out it may very well be your generator. I just had my generator rebuilt at a local auto electrical shop. New bearing,brushes,cleaned and painted for around $40.

TR3driver
07-15-2009, 01:13 PM
Hmm, I just realized, that is a TR3 regulator. All TR4s (and TR3A after TS60K) should have push-on connectors instead of screw clamps.

Anyway, yes, anything over 12.8 would indicate that it's charging.

As I recall, the workshop manual isn't too good at on-car troubleshooting. The manual I linked to above gives a better sequence of tests, IMO.

DNK
07-15-2009, 01:19 PM
Randall, I'm no 4 expert but those look like push connectors to me.

TR3driver
07-15-2009, 01:24 PM
Randall, I'm no 4 expert but those look like push connectors to me. We must be looking at different photos, Don. I'm looking at
https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/download/Number/17729/filename/Reg.jpg
above, and the screw heads are clearly visible.

NickMorgan
07-15-2009, 01:41 PM
Yes, that is certainly an early regulator, but that shouldn't matter.
Does the red light come on at all?
I would suspect the dynamo (generator) as first culprit and possibly the regulator next. The generator will give a constant problem while the regulator may me more intermittent.

DNK
07-15-2009, 01:43 PM
Randall, thought you were talkin about the gen
I'll go back to my hole now.
Should know better to question HWKA

:laugh:

doughairfield
07-15-2009, 01:51 PM
The red light does not come on at all, never has. I read in the repair manual you can disconnect the yellow/brown wire and ground it and the light should come on. If it doesn't you probably have a regulator problem, so I am going to do that tonight.

Question, I noticed that if I rev up the engine to about 3500 the low power problem seems to go away. Wouldn't that lean more towards a generator problem as getting it spun up fast enough would produce enough power to run the engine cleanly, and at low speeds it was not generating sufficient power?

My logic could be totally off here too.

You're right, the repair manual is weak when it comes to trouble shooting, very hard to understand.

TR3driver
07-15-2009, 02:13 PM
The red light does not come on at all, never has.I would guess that explains the missing wire then. Whoever installed that early control box just forgot to connect the wire to the dash lamp. The red light should come on as soon as you turn the key on, then only go out once the engine is started and the generator is working.<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Question, I noticed that if I rev up the engine to about 3500 the low power problem seems to go away. Wouldn't that lean more towards a generator problem as getting it spun up fast enough would produce enough power to run the engine cleanly, and at low speeds it was not generating sufficient power?[/QUOTE]The regulator has a resistor that supplies some field current to the generator all the time, basically just enough to operate the ignition at higher revs (when the generator output is higher). At least in my experience, generator failures tend more towards "all or nothing" (though partial failures are certainly possible too).

So no, I wouldn't say your observation leans towards much of anything. There is just no substitute for making the tests.

Note that it is also entirely possible to have both generator and control box fail at the same time. A fault in one can easily lead to a problem with the other. So it's important to test again after changing one or the other.

If you really want to just change components rather than doing the trouble-shooting, IMO you should change them both at the same time. Even that is not a 100% guarantee, as even 'new' units are sometimes bad, but it's probably your best shot at solving the problem.

Adrio
07-15-2009, 02:25 PM
I ma not trying to b funny hear, in fact I confess to haveing a similar problem and going through the electrical troubleshooting route (since I am an electrical type guy) only to find at the end it was a loose fan belt. Have you checked the fan belt?

The reference Randall gave you for making those tests. I used them when I should have been tightening the belt.

doughairfield
07-15-2009, 02:37 PM
Randell,
Thanks, I'll check the wire for the light, I would like that to work properly. And thanks for the Lucas test manual, I think I can make it through there to do the tests and get this narrowed down. I'm all for doing the testing, and wife willing, will tonight. I'm going to test the voltage on the battery first with a full charge and see where that's at and go from there.

I have not checked the fan belt, that is a good suggestion. What did you use to gauge how tight it should be?

DrEntropy
07-15-2009, 02:54 PM
And nobody yet mentioned making sure there's a good bulb in the iggy lamp socket.

Adrio
07-15-2009, 03:01 PM
I have not checked the fan belt, that is a good suggestion. What did you use to gauge how tight it should be?

I used my fnger. I think the manual says something like X inches of play in the middle of the long span. I am at work (though you would not know it from my postings) and don't have access to the manual now. Maybe somone who has it handy (or a better memory then me) can help out.

martx-5
07-15-2009, 03:56 PM
Here's the wiring diagrams (https://www.advanceautowire.com/tr24a.pdf) for the TR2-TR4A. Pick the appropriate one (tr4), and it will show you how the red ignition/generator light is wired in. You can check the bulb with an ohm meter. Probably about 35 ohms (4 watt bulb), since that's the figure we use on our alternator testers at work. It might be higher or lower if the wattage of the bulb is different.

doughairfield
07-15-2009, 03:59 PM
Nice, thank you Art. Is there a special tool to take that notched ring off around the red light housing? Or do you just have to be clever.

TR3driver
07-15-2009, 04:20 PM
There was a fellow selling the tool on eBay, but I don't have a link handy. I used needle-nose pliers for many years, then finally made my own.

But, there is no reason to remove it unless it's broken or you want to paint the dash or something; the bulb holder just pulls out of the back of the red plastic piece.

As you'll note in Dan's diagrams, the "ignition warning" red light is a special case, it is NOT grounded. One side of the bulb connects to the 'D' terminal at the control box (which should be hot when the engine is running); the other side connects to the ignition circuit (white wire) (hot when the key is on).

Also note that the bulb's resistance changes dramatically when it is 'lit', so you can expect to find that it has a much lower resistance than it's 2.2 watt power rating would indicate. But all you are really looking for is continuity through the bulb, it's exact resistance does not matter.

Book says 1/2" - 3/4" when pressing on the belt on the longest run (between crank &amp; generator.

martx-5
07-15-2009, 04:38 PM
Also note that the bulb's resistance changes dramatically when it is 'lit', so you can expect to find that it has a much lower resistance than it's 2.2 watt power rating would indicate.

Randall, would that explain why we use a 35 ohm resistor on our bench testers (we don't use a bulb) instead of say 65 ohms for a 2.2 watt bulb?? I never realized there was such a dramatic change in resistance when an incandescent bulb lights. Here I am thinking we're simulating a 4 watt bulb.

TR3driver
07-15-2009, 05:11 PM
I don't think so, Art. I'd say the difference is due more to the difference between alternators and generators. A DC generator starts mostly on the residual magnetism left in the housing (hence the need to 'polarize' them, what you are really doing is magnetizing the housing &amp; pole pieces) and doesn't need the light at all. But many (not all) alternators rely on the current through the bulb to 'tickle' them into life. The rotor doesn't retain enough magnetism to overcome the voltage drop through the diodes.

When I installed an old Ford Motorcraft alternator in my TR3A, I found that the bulb was too small for the alternator to start reliably, and added a resistor across the bulb. But it was less than 35 ohms, more like 10 as I recall. My Chevy also had a resistor across the bulb (so it's alternator would keep working even with the bulb burned out), that was around 10 ohms as I recall.

Likely your tester works OK with a higher resistance, because you spin the alternator faster during testing. The TR3A alternator would start with just the bulb, if you revved it to 6k rpm or so (at the alternator).

martx-5
07-15-2009, 05:39 PM
Actually, we slowly bring the alternators up to speed to record the "turn-on-speed" which is usually between 900-1500 rpm alternator speed. We set these parameters in the database for each alternator on a pass or fail. Of course, pulley size of the alternator is factored in. It's one of the tests the alternator must pass. We do not rev it high to get them going...quite the opposite. We monitor the voltage at the "light" circuit before we start spinning it, and after turn-on, simulating the light circuit. We do this so the operator doesn't have to monitor anything. Every test during the cycle is "pass" or "fail".

Curious thing about the lower resistance. We have an old tester that is used occasionally for Delco 10SI units, and that has an actual light circuit. To get the 10SIs to fire up, I did have to add a resistor across the light circuit to get them to activate, yet I don't have the problem on our regular testers with the 35 ohm resistor.

I'll take a look at the wiring diagrams of the testers tommorrow just in case I'm missing something.

Thanks for the input.

TR3driver
07-15-2009, 06:09 PM
I'll see if I can dig out the shop manual for the Chevy. That's where I copied the resistance from. I just checked "The 12v Doctor's Alternator Book" and it says typical values are from 75 ohms to 300 ohms (with a 5 watt light).

doughairfield
07-15-2009, 08:18 PM
I just got the battery back in the car. Before being hooked up, I was at 13.5 volts. After hooking it up and cranked it up, I was down to 12.8. Trying to do some further testing tonight.

TR3driver
07-15-2009, 08:54 PM
Art, I found the Chevy manual, and it does say 10 ohms. But it also says that it is needed to protect the diode trio, so I'm not sure what to make of that. My car had a 15SI but the wiring was the same as the 10SI.

doughairfield
07-15-2009, 11:15 PM
Trying to make some sense of the Lucas Test PDF you sent. In step 1 it says to "Disconnect leads from generator." I assume those to be the two leads on the generator, then take the DMM and attach one lead to the D terminal and one to ground. Where is the D terminal on the generator? I know there is a D terminal on the regulator, is that what it's referring to?

TR3driver
07-16-2009, 01:16 AM
Right, two wires to the generator. The D terminal on the generator is the larger one (which is also linked to the D terminal on the regulator). The F terminal is the smaller (likewise linked to the F terminal on the regulator).

For test 1, voltmeter from D terminal on generator to ground (generator case).

For test 2, link F to D at the generator, voltmeter from either one to ground.

These two tests basically verify the generator, without the regulator in the circuit (so no question about where the fault lies). If either test fails, stop and repair the generator; then retest until it passes both tests.

For tests 3 and 4, the two wires get reconnected at the generator, and disconnected at the regulator (these tests basically just verify that the wires are good).

Then follow part 2, starting on page 5 of the booklet (this is the section that applies to the TR2-4 regulator).

TR3driver
07-16-2009, 01:18 AM
BTW, I have a better scan of that booklet, which is small enough to email. It's on the web somewhere (but I forget where offhand). If you (or anyone) would like a copy, PM me your email address &amp; I'll shoot it right over.

doughairfield
07-16-2009, 09:16 AM
Randall,
Just tried to send you a PM, but you seem to be over your limit. The burden of being popular.

Thanks for clearing that up, I'll do the testing when I get home.

So I realized last night, the Voltage Regulator on my 64 TR4 seems to be from a TR3. Has only 5 terminals instead of 6, and they are screw on. This sucks because my repair manual is for a TR4 with the different Regulator. I'm wondering if that is why the red light never comes on, it may just not be wired. Was the TR3 VR in the TR4 a common thing or someone back in the day just made it work?

TR3driver
07-16-2009, 09:53 AM
The TR3 and TR4 regulator are functionally interchangeable (actually, the switch was during the TR3A run). With the screw-terminal version, there are just two wires under the 'D' screw; one for the generator armature and one for the warning lamp on the dash.

Not a common replacement AFAIK, but nothing wrong with the swap. No doubt someone needed to replace the regulator and the screw-terminal version was available.

PM situation should be cleared up now. I thought I had deleted all those old messages, but guess I was mistaken.

doughairfield
07-17-2009, 07:01 PM
Ok, just got Test 1 complete, Randall et. al. if you could verify my logic in understanding the tests and my findings it would be much appreciated.

connected negative of MultiMeter to D terminal on the generator and postitive lead of MM to ground.
At idle I was getting 1.3 volts. As the engine speed went up towards 3K rpm, the voltage increased to 2.5 volts @ 3K rpm. My understanding is this is Reading C on test 1, Rising volts with rising speeds - thus internal short between D and F terminals, examine field coils and replace if necessary. Anyone concur with these findings?

I understood reading A to be 2-4 volts from idle up to 3K rpm, correct?

DNK
07-17-2009, 07:07 PM
Is this electronics 100.
If not I'm in the wrong class.

TR3driver
07-17-2009, 07:23 PM
Doug, I believe your results fall within case 'A'. I believe it should be read as "The voltage should be within the range 2-4 volts when the generator rpm is 3000 rpm."

In any case I am reasonably sure that your results do not fall within case B (open brush or armature); or within case C (field-armature short). For a field-armature short, the voltage would be above normal charging voltage (eg 20 volts), not just 2.5.

I would proceed to test 2. I hadn't realized it wasn't in this book, but the workshop manual warns not to let the generator voltage exceed 20 volts during test 2, as higher voltage may damage the insulation (ruining an otherwise working generator). That's part of the reason these things are so fragile, they will happily turn out enough voltage and/or current to kill themselves, without the regulator to keep them under control.

TR3driver
07-17-2009, 07:33 PM
Is this electronics 100.
If not I'm in the wrong class.
Don, this is closer to the "electric shop" class I had in high school. No electronics involved, just relatively simple electro-magnetics. (Which was a disappointment to me at the time, I could have taught that class!)

Should we start with making an electromagnet from a nail &amp; some wire? :laugh:
https://www.iit.edu/~smile/ph9528.html

DNK
07-17-2009, 09:57 PM
Must have missed that class when I took Home EC :laugh:

angelfj1
07-18-2009, 07:32 AM
Is this electronics 100.
If not I'm in the wrong class.

Should we start with making an electromagnet from a nail &amp; some wire? :laugh:
https://www.iit.edu/~smile/ph9528.html

Not much more advanced than these TR's :devilgrin:

DrEntropy
07-18-2009, 08:56 AM
Prezactly, Frank!! It'll work in th' bottom of a bucket of err....
well, it'll just WORK, even if it's only HALF right. :laugh: :thumbsup:

TR3driver
07-18-2009, 09:29 AM
Hmm, maybe it would help some to state a bit of how a DC generator works. Really just two electromagnetic principles are involved, the main one is :

1) Moving a wire through a magnetic field induces electricity in the wire.

and an opposite effect :

2) Current flowing through a wire generates a magnetic field around the wire.

So, the generator generates electricity by moving a wire (actually a whole bunch of wires wound around the armature) through a magnetic field.

Since we need to control how much electricity is generated, the magnetic field is made variable, by using electricity flowing through a wire to generate it.

These effects are pretty weak with just a single wire, so we use lots of turns of wire plus iron to both hold the wires and focus the magnetic field. Everything else is just mechanical engineering (like how to connect moving wires to non-moving wires).

So, the main purpose of the control box is to control how much the generator generates; both to avoid overcharging the battery and overheating the generator (from too much current). In a TR control box, this function is handled by the voltage regulator relay (which doubles as a current regulator as well); which shuts off the current to the field windings whenever the voltage or current get too high.

There is a secondary problem, which is that if we leave the generator connected to the battery with the engine not running (generator not turning), current will flow from the battery through the generator (which after all is conceptually just a length of wire) and discharge the battery. So, the control box also has to disconnect the generator from the battery when the generator is not turning (or turning too slow to be useful). This is the cutout relay.

Ok, maybe we're into Electricity 101 here. Are there any questions?

doughairfield
07-22-2009, 09:54 AM
Ok, so I was able to get a bit of time last night and went through testing the generator via the Lucas repair manual. Everything from the generator back to the the Voltage Regulator looks good. I was getting up in the neighborhood of 45 volts when I linked the 2 D and F terminals on the generator, which should be plenty. I'm moving on to Part 2 Test 5 tonight.

doughairfield
07-22-2009, 03:35 PM
I was reading through the Lucas manual for Part2 Test5, was hoping someone could clear up a few questions.
1. the line "On no account should these tests be made with the battery in circuit"
Does that mean to disconnect the battery? I assume no but want to be sure.
2.In Test 5 when it says Engine Stationary, that means don't have the engine running, correct?
3. What(where) are the cut out contacts? Is that the space between the core and the armature?

martx-5
07-22-2009, 03:52 PM
1. That means to <span style="font-weight: bold">disconnect</span> the battery.

2. Engine <span style="font-weight: bold">not</span> running.

3. I assume that they are talking about the generator cut-out contacts that are <span style="font-weight: bold">inside</span> the voltage regulator. The service manual does make mention of armature (the part that moves) on the cut-out, but they use the word "coil" rather then core...but this is a TR3 manual.

In my manual for the TR3 regulator, the cut-out is on the right side when viewed with the wire connections on the bottom. I don't know if it's the same for the TR4, as somewhere along the way I believe a third coil was added.

doughairfield
07-22-2009, 03:58 PM
1. oh, ok, good to know.
2. as I assumed
3. I actually have the 5 screw TR3 type voltage regulator on my TR4. so the cut-out is the one with more copper wire wrapped around the cylinder and the regulator is the one with just a few wires?
The step says to isolate the battery by placing a piece of dry card between the cut-out contacts. Is that in addition to disconnecting the battery? Or is that essentially removing the battery from the circuit?

BTW, I have been referencing the Lucas repair manual I received from Randall. I will be glad to send you a pdf copy if you want, just DM me your email.

martx-5
07-22-2009, 04:11 PM
OK, I think that some of the info you posted might have been taken too much out of context. I'm getting a bit confused at the moment as far as battery isolation is concerned. Send me that pdf. You have my e-mail access if you click on my forum name and go to profile.

Edit again: I can't tell you which coil has what kind of wire as I don't have a seperate voltage regulator in my TR3 anymore, but it's the one on the right when the wire connectors are at the bottom...wire connectors south, cut-out east. :smile:

doughairfield
07-22-2009, 04:30 PM
Ok, just sent you the manual. Just trying to work through tests 5 and 6 in part 2.

TR3driver
07-22-2009, 04:36 PM
The step says to isolate the battery by placing a piece of dry card between the cut-out contacts. Is that in addition to disconnecting the battery? Or is that essentially removing the battery from the circuit?The cardboard removes the battery from the circuit.

The regulator relay is the one where the contacts close when the relay is not energized. The cutout closes when it is energized.

Twosheds
07-22-2009, 04:42 PM
In the vibrating-point style voltage regulators that I have messed with (aircraft ones) the reverse-current cut-out contacts are the only ones of the three spools that are held open by a spring. The other two, voltage regulator and current limiter, are held closed by spring. This should help identify the reverse-current cut-out contacts.

TR3driver
07-22-2009, 04:43 PM
When they talk about "core" in the control box, they mean the steel rod through the center of the winding on each relay. The "armature" is the part that moves.

doughairfield
07-22-2009, 06:22 PM
Do I still need to disconnect the battery?

TR3driver
07-22-2009, 06:40 PM
Do I still need to disconnect the battery?
No, just sticking some thin cardboard (eg matchbook cover) into the cutout contacts is all that is needed.

TR3driver
07-22-2009, 06:45 PM
I don't know if it's the same for the TR4, as somewhere along the way I believe a third coil was added. Just caught that, Art. The TR series continued to use a 2-coil setup until the TR5/250 got an alternator. The 3-coil regulators were used on other Triumphs though, like the early Vitesse, GT-6 and maybe Spitfire.

doughairfield
07-23-2009, 08:04 PM
Ok, I made it through tests 6 and 7. On Test 6, my voltage was a bit low, so I turned the adjustment screw on the back of the regulator about 3/4 of turn to bring the voltage up to 16 at 3K RPM. When I did this I began to see some arcing where the fixed contact adjustment screw meets the contact plate above the bobbin core. Is this normal behavior?

On test 7, after removing the card board from between the cutout, I got battery voltage from terminal A and ground. Pass

Now, on Test 8, I did not get the expected voltage increase of .5-1 volt with the engine running, I actually read slightly under battery voltage. So the voltage isn't low, it's just lower than expected. Any ideas here? Is it possible the cutout, though closing is not closing properly and over time the lower voltage drags the battery down?

For test 9, the cutout closes pretty much right after the engine starts, so I assume that passes.

TR3driver
07-24-2009, 04:52 PM
The arcing is normal, in fact I'm surprised you didn't see it before. The points close to call for more output from the generator and then open when the output is high enough. When they open, there is some inductive kickback from the field windings that causes the spark. 'Old school' electrics here, the contacts are supposed to just live with the spark.

Your test 8 results definitely indicate a problem, but I'm not sure what. It might just mean the cutout is closing too soon; does the voltage go up if you increase the engine speed just a bit (say 1500 rpm)?

Check the voltage back on the D terminal; if it is different than A with the cutout closed then there is a definite problem with either the cutout contacts or the connections to them.

In case you don't have it, here is the control box diagram.

TR3driver
07-24-2009, 04:55 PM
In the diagram above, the "series" coils are the heavy wire you see on the outside of the relays. Since it's just wire, once the cutout closes, the D terminal should be effectively connected directly to A (and A1), so that's why the voltage should be the same.

doughairfield
07-24-2009, 05:38 PM
Ok, so the battery voltage does not go up in test 8 when the engine speed increases, just stays at battery voltage.

I tested contacts A and D, with the engine running. A was at battery voltage of 12.55 and D was at 16.5, so they are different. Also to note, during my testing the cutout has always closed about the 3-5 seconds after starting the engine. So is it closing too soon?

TR3driver
07-24-2009, 11:43 PM
Ok, so the battery voltage does not go up in test 8 when the engine speed increases, just stays at battery voltage.

I tested contacts A and D, with the engine running. A was at battery voltage of 12.55 and D was at 16.5, so they are different. Also to note, during my testing the cutout has always closed about the 3-5 seconds after starting the engine. So is it closing too soon? Perhaps, but the important thing to figure out now is why it is not connecting D to A.

Some quick probing at the cutout contacts with your voltmeter should tell you if the contacts aren't conducting (which could maybe be fixed by cleaning and adjusting them), or if there is a broken wire/connection in the unit. The armature (which on my unit is silver-colored) should be connected to D (so you should find the 16.5 volts there), while the contact arm (which on mine is copper colored) should be connected to A.

If you find different voltages right at the relay, then it has to be the contacts that aren't making contact. Check the air gaps per the workshop manual; then clean the contacts with a scrap of newspaper or cloth soaked in carb cleaner. And try again. If that doesn't do it, you may need a new control box.

doughairfield
07-29-2009, 09:20 AM
Ok, I tested out the contacts at the cutout with a voltmeter. At first, I was getting low voltage on the contact blade and the armature tongue. I stopped the engine, then restarted just to verify. I don't know if I did something in the original testing, but I noticed that the cutout was opening and closing quickly and the regulator was almost vibrating. I adjusted the regulator output just a touch and all seemed to start working. I had 16 volts on the cutout and proper voltage from terminal D. Also, the Ammeter on the dashboard also seemed to be indicating charge. So of course I drove it for about 15 minutes and all seemed good. Turn the lights on and the ammeter dipped right then back to 0. BUT, now, with the engine at a high idle,~1200 rpm, the green ignition light flashes once every 3 seconds, I don't know what this means. And the more I drive it, the ammeter is bouncing all over the place. Yesterday it even went all the way to the left I guess to indicate max charging and the car shutdown. It seems I'm now having an intermittent problem with the control box now?

This is a total n00b question, but how do I test the battery to see if it is low? To make sure it is not being over charged, or is being charged. Would just testing the battery for voltage tell me this? It is consistently reading 12.5 to just over 13 volts so far. If it is going dead will it register less voltage?

Andrew Mace
07-29-2009, 10:40 AM
BUT, now, with the engine at a high idle,~1200 rpm, the green ignition light flashes once every 3 seconds, I don't know what this means.I think it means that you're color-blind...or that the wrong bulb is in the wrong holder. Ignition lights are usually red on Triumphs; flasher indicator lights are usually green! :devilgrin:

Seriously, though, that does sound a bit odd....

doughairfield
07-29-2009, 10:43 AM
I actually am a bit color blind. Plus, I know this car had a frame off restoration about 25 years ago, there is not guarantee everything was put back together correctly. I just found 2 different size disc rotors on it Saturday.

Is it possible that the flashing light light, though should be the red one is indicating an over charging?

Andrew Mace
07-29-2009, 11:17 AM
I actually am a bit color blind. Plus, I know this car had a frame off restoration about 25 years ago, there is not guarantee everything was put back together correctly. I just found 2 different size disc rotors on it Saturday.
Oops! :wink:


Is it possible that the flashing light light, though should be the red one is indicating an over charging? I'd think it might be indicating that the regulator is cutting in and out?

tdskip
07-29-2009, 11:18 AM
Guys - doesn't a flickering light like that sounds like Doug is getting a warning about inadequate juice from the generator, albeit through a wrong-color (per stock) warning lamp. The alt meter jumping around like that and the car suddenly cutting out suggests, as others pointed out, you have a loose ground somewhere. Would that explain a lot of the symptoms?

Doug - where did you get to in your testing of the items Randall was walking you through?

Twosheds
07-29-2009, 11:32 AM
Is it possible that the flashing light light, though should be the red one is indicating an over charging? I'd think it might be indicating that the regulator is cutting in and out?[/quote]

Sounds to me like the reverse-current cut-out opening and closing. The light is in parallel with the reverse-current cut-out contacts, if it's like the aircraft ones. When the generator voltage is below a set point, the contacts are held open by a spring, isolating the generator output from the electrical system, so the batery is powering any electrical loads. Battery current flows through the bulb, illuminating it. When the generator voltage rises to a set point, the current through the coil creates a strong enough magnetic field to overcome the spring and closes the contacts. Now the generator runs the electrical loads. Both sides of the bulb are at the same voltage, and it extinguishes.

TR3driver
07-29-2009, 12:17 PM
Ok, I missed something Doug. You said much earlier that the "red" light on the dash did not come on when it should (key on, engine off). Did the other warning light (which should be green for the turn signals) come on? Or have you done something to make the ignition warning light start working? Does it come on now with the engine stopped and the key on?

My guess, with the information so far, would be that the contacts in the regulator are intermittent, plus the resistor is open or intermittent. That would explain why you saw the voltage regulator contacts start working during a test above; plus the cutout contacts started working while you were testing them. The open resistor plus intermittent VR contacts would explain the cutout chattering and the flashing warning light (which in effect indicates when the cutout is open).

Not sure if Radio Shack still carries them, but a contact burnishing tool (https://www.mcmaster.com/#4575a71/=2yhult) would be best for a more thorough cleaning of the control box contacts. Using harsher abrasives creates a rough surface that will burn and cause exactly the kind of symptoms you are seeing.

With just a voltmeter, it's hard to sort out a battery's condition from it's state of charge. But unless your battery is doing something extremely strange, it wouldn't cause the symptoms you are seeing. The usual definitive test for a battery is to charge it, and then check how well it performs under load. You have effectively done that, by charging it with jumper cables and then using it to start the car. That's enough to show that it is fundamentally still a battery, although it might still be weak or have a shorted cell. But the charging system would try to charge it anyway, and that is where your problem is.

TR3driver
07-29-2009, 12:24 PM
Hmm, not sure if I explained that clearly enough. I'm basically agreeing with John, the blinking light probably indicates that the cutout contacts are opening and closing.

The cutout is supposed to open when the generator starts drawing current from the battery (as it will do when the engine stops). But if the VR contacts were not making connection, and the resistor was not working to supply a minimum current flow into the field windings of the generator; it would start drawing current with the engine running. That should cause the cutout contacts to open.

That's a really obscure quote there, John. Was the movie good?

Twosheds
07-29-2009, 02:14 PM
I haven't seen the movie (The Moon and the Sledgehammer), Randall. I was absolutely captivated by that quote and the review I read on a blog. I can't justify, what was it? 20 Pounds plus shipping? for the DVD.

But the idea of disassembling a magneto in a place where there are monkeys about just fascinates me.

I'm just an obscure quote kinda guy I reckon.

doughairfield
08-02-2009, 05:58 PM
Randall - The red light has never come on as long as I've had the car, but that's only a few months. With the engine off and the key on the green light is on but dim. With the engine running the green light is still on, and when the VR starts acting up, the green light flashes once every 3 seconds.

The problem now seems intermittent since I turned up the output voltage on the VR, like there is something going bad and getting worse.

The cutout is most certainly chattering. That is it is opening and closing fairly rapidly at 1000 to 2000 rpm, and the Ammeter on the dash is dancing all over the place. But occasionally everything seems to work. But when I really rev up the engine, it stays shut.

I have also noticed intermittent charging from the VR, sometimes I see the little sparks dancing between the contacts, and other times like now I don't see them.

It sounds like it may be time to just change out the voltage control box. I have one that has the screw on terminals which I think is for a TR3. I could replace it with that one, or the one for the TR4 that has the Lucar contacts. Is there an advantage to getting one over the other?

TR3driver
08-02-2009, 07:25 PM
Well, I would want to sort out what's up with the warning lights before replacing the box. It sounds to me as though the previous owner (or his mechanic) has bolluxed up the wiring to at least some extent. That's probably not the direct problem, but I'd still want to get it sorted out.

The red light should come on, brightly, when you turn the key on with the engine not running. One side gets 12v from the ignition switch, the other side is wired to the generator 'D' terminal (so at this point the generator is serving as the ground for the light).

The green light should come on only when the turn signals are on, and it should blink with the turn signals. It gets it's power directly from the 3rd terminal on the flasher, and should have a ground wire to the ground point behind the instrument panel.

It almost sounds like your DPO has wired the two together somehow, so the flashing might be coming from the turn signal flasher somehow.

I would also use an ohmmeter to check the resistor inside the control box. Disconnect the wire from the F terminal, and connect the ohmmeter between F and D. You should initially see 1-2 ohms. Now open the VR contact by holding the armature down with your finger. The reading should rise to around 60 ohms.

At this point, I don't think there is any functional reason to choose the Lucar over the screw terminals. Go with whatever is easy, and/or suits any leanings you have towards originality. Note that those oversize Lucar terminals are a bit hard to find, you'll likely need to order them from one of the LBC suppliers.

doughairfield
08-02-2009, 08:59 PM
Will I need to disconnect the battery before testing the resister and moving the armature on the VR?

It does seem like the green like is wired like the red light should be since it is on all the time AND blinks with the turn signal, I"ll try to get that sorted out tomorrow.

Thanks again for the help.

TR3driver
08-02-2009, 11:40 PM
Will I need to disconnect the battery before testing the resister and moving the armature on the VR?Won't hurt anything if you do, but it's not necessary. The cutout contacts should be open, to isolate the VR contacts from the battery.

doughairfield
08-03-2009, 05:09 PM
Ok, with the armature open, I am only getting .5 ohms of resistance. It actually fluctuated a few times between what I expected of about 1.5 ohms but then settled down to .5 after a second. Other times it just went .8 down to .5 or .4. Once I close the VR armature, I get 67 ohms or resistance. is that initial resistance too low?

I'm in the process of sorting out the red light thing.

martx-5
08-03-2009, 05:53 PM
That lower resistance sounds fine to me. Looking at the control box schematic, any resistance is just between the points and any other connections in there. Theoretically, I guess it should be zero. I think Randall just gave you a low number of 1-2 ohms as what you would probably see.

If I'm seeing this wrong Randall, please correct me, but that's what I see in the schematic.

doughairfield
08-03-2009, 08:55 PM
hum, well I'm kind of at a loss as to where to go now with this problem.

TR3driver
08-03-2009, 10:52 PM
Yeah, the lower resistance shouldn't be a problem; I just meant that it should be nearly zero.

Seems like all the evidence points to your control box being flakey. You clearly saw the cutout contacts not making connection, then after fiddling with it awhile, they started working. Same story with the VR contacts, twice now.

I would fix the problem with the lights, clean the contacts again just for luck (preferably with a contact burnishing tool), and try it one last time. If it still doesn't charge, or the light acts funny, time for a new box, IMO.

doughairfield
08-04-2009, 10:19 AM
I wedged myself under the dash last night and saw that the red light is connected with 2 wires, but then disappears into the tapped up bundle of wires and then over to the right side and I assume out through the firewall.

So would I test the 2 leads at the red light for an open circuit to see it is even operational? After that, would I just pull all the tape off that bundle of cable back trough the firewall? I assume it should terminate to the fuse box? And the fuse box gets power off the VC?

martx-5
08-04-2009, 12:59 PM
I don't know if you have a copy of the wiring diagram, so here's one from Advance Auto Wire. (https://www.advanceautowire.com/tr24a.pdf) It should help sorting out which wires go where and what their colors are before you go ripping into the harness.

Edit: You will notice that there's a white wire on one side of the light going to the ignition switch, and a brown/yellow on the other side going to the "D" terminal of the control box (voltage regulator). Or, at least that's what is supposed to be there.

TR3driver
08-04-2009, 01:10 PM
I wouldn't unwrap the bundle except as a very last resort.

Here's how I would attack it:

Pull both the 'red' and 'green' bulb holders out, and remove the bulbs. Check all 4 leads with a test lamp, to see if they have 12v on them, or a path to ground. (You're expecting to find that 3 of them have a path to ground, at this point.)

Turn the key on, and check to see if one of the leads now has 12v. I don't know just how the white circuit was routed on a TR4, but the factory diagram I have handy seems to indicate it would be the same as a TR3 and run directly to the ignition switch. The white circuit does not go to the fuse block on a TR4, so there is no reason for it to run into the harness. In fact, there should only be one wire from each bulb holder that runs into the harness; one to the control box.

Turn the key back off, and find the second wire on the 'D' terminal of the control box (the one that doesn't go to the generator). Disconnect it from the control box, and supply 12v to it. Now check again at the bulb holder, to see if one of the wires now has 12v on it.

Armed with that information, replace either or both of the wires to the 'red' light with wires that run to the correct connections. For now you can just tape off (insulate) any removed wires; maybe later you'll find where they belong.

TR3driver
08-04-2009, 01:22 PM
and a brown/yellow on the other side going to the "D" terminal of the control box (voltage regulator). Oddly enough, the diagram you linked to shows that wire as yellow, instead of brown/yellow. It was solid yellow on the earlier cars, but the TR4 factory diagram I have does show brown/yellow.
https://i258.photobucket.com/albums/hh260/TR3driver/th_TR4wiringdiagram.jpg (https://s258.photobucket.com/albums/hh260/TR3driver/?action=view&amp;current=TR4wiringdiagram.jpg)

Bottom line, don't get too hung up on the colors of the wires :laugh:

doughairfield
08-04-2009, 02:22 PM
Randall, you mentioned something above, the second wire from the D terminal which should goto the redlight. I noticed I don't have but one wire on the D terminal, and it goes to the generator. I'll see if I can figure out how the green light is wired and where the wire is that is supposed to goto the red lamp.

Andrew Mace
08-04-2009, 02:51 PM
Doug, you might be onto something here with that "missing" wire. What Randall notes about the two yellow wires (one to generator and the other to warning light) also goes for the Herald and Triumph 10, both of which used virtually the same voltage regulator (control box). Hate to say it, but it sounds like you might just need to dig well into your bundle o' wires to see what sort of havoc a previous owner might have wreaked. :frown:

doughairfield
08-04-2009, 02:57 PM
Yes, that very well could be the case but I hope it isn't. Although, I know the guy who had the car before me for almost 20 years, and he never had a charging problem with it. Of course it all started once i bought it. And the cutout flutters at 1000 to 2000 rpm. Everything just seemed fine and then it started acting up and got worse and worse. But I'm still going to investigate as much of the wiring as I can.

TR3driver
08-04-2009, 03:27 PM
Of course it all started once i bought it. Where have I heard that story before ?
:devilgrin:

martx-5
08-04-2009, 04:52 PM
and a brown/yellow on the other side going to the "D" terminal of the control box (voltage regulator). Oddly enough, the diagram you linked to shows that wire as yellow, instead of brown/yellow. It was solid yellow on the earlier cars, but the TR4 factory diagram I have does show brown/yellow.


Randall, I think that you didn't scroll down far enough to the TR4 diagram, as it does show brown/yellow on that, but yellow on the TR2/TR3.

TR3driver
08-04-2009, 04:57 PM
Oops! Looks like you're right, Art. My bad.