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TR4/4A HELP not able to get my TR4 started

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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.
 
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.
 
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 a PDF file with suitable tests. Note that even a cheap DMM makes a adequate substitute for the prescribed moving coil voltmeter.
 
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?
 
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.
 
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.
 
Randall, I'm no 4 expert but those look like push connectors to me.
 
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.
 
Randall, thought you were talkin about the gen
I'll go back to my hole now.
Should know better to question HWKA

:laugh:
 
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.
 
doughairfield said:
The red light does not come on at all, never has.
Click to expand...
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.
 
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.
 
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?
 
And nobody yet mentioned making sure there's a good bulb in the iggy lamp socket.
 
doughairfield said:
I have not checked the fan belt, that is a good suggestion. What did you use to gauge how tight it should be?
Click to expand...

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.
 
Here's the wiring diagrams 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.
 
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