TR4/4A TR4A voltage regulator help

[JDstr4a]

I have a constant ignition light, so popped the cover on the control box. The regulator contact was closed, so I cleaned it up and did the manual adjustment. Seems like the springs that hold the armature are permantly bent, which made the gap adjustment difficult. Finally got it, but when I went to check the voltage the shop manual says rev to 3000 and check open circuit voltage, with cardboard in the contacts. The picture showing adjusting looks like F and ground? I'd like to confirm before just poking around wih the meter. Any other checks or hints to narrow down the regulator/generator/wiring issue would be greatly appreciated. The amp meter shows just barely off center to the charge side and the ignition light still stays on.

Still tinkering..
JD

 

[TR3driver]

Seems like the springs that hold the armature are permantly bent, which made the gap adjustment difficult.

Can you amplify a bit on that? Normally you put a feeler gauge between the pole piece & the armature, then hold the armature against the feeler gauge while you first tighten the two screws that support the armature; and then screw the fixed contact in so it just touches the moving contact.
I generally don't even bother backing off the spring, even though the book says to. It just means you have to press down a bit harder to hold the armature against the feeler gauge.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Finally got it, but when I went to check the voltage the shop manual says rev to 3000 and check open circuit voltage, with cardboard in the contacts.[/QUOTE]Note that the 3000 rpm is <span style="font-weight: bold">generator </span>rpm. The engine will be just above fast idle, 2000 rpm or so. The exact speed isn't important, though. And the (thin) cardboard goes in the cutout contacts, not the regulator contacts.<div class="ubbcode-block"><div class="ubbcode-header">Quote:] The picture showing adjusting looks like F and ground?[/QUOTE]The measurement should be taken between D and ground. <div class="ubbcode-block"><div class="ubbcode-header">Quote:] The amp meter shows just barely off center to the charge side and the ignition light still stays on.[/QUOTE]
That is suggestive of the battery polarity having been swapped at some point, or there being some other wiring issue. Normally I'd expect to see a slight discharge (through the ignition) as the red light should be showing that the generator output is not connected to the battery (cutout open) and hence no charging is possible. What happens with the engine not running?

There are some more explicit troubleshooting instructions at
https://docs.google.com/viewer?a=v&p...Fm&hl=en_US

 

[JDstr4a]

thanks Randall alot of good info. the spring steel that goes from the back of the armature up under the securing screws holds the the whole amarture askew so much the tension spring is real close to the windings and the voltage adjusting screw is almost all the way in just to make contact.
My error on the amp meter, it is barely on the discharge side when running or with just the ignition on. I just noticed my amp gauge is opposite of what is shown in the original owners manual.
Just looked at the cutout and the contacts are open and the armature is resting on the stop arm. That would seem to be opposite, so I guess I'll go through the manual adjust on it next.

thanks again for the guidance and the link!
JD

 

[TR3driver]

the spring steel that goes from the back of the armature up under the securing screws holds the the whole amarture askew so much the tension spring is real close to the windings and the voltage adjusting screw is almost all the way in just to make contact.

That does sound odd. It's important that the armature rest squarely on the pole piece & feeler gauge; if the gap is not square then it will be difficult or impossible to get the regulator to work properly. If it won't sit squarely on the feeler, then I'd be looking for something to bend back into place, or a new regulator.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Just looked at the cutout and the contacts are open and the armature is resting on the stop arm. That would seem to be opposite, so I guess I'll go through the manual adjust on it next.[/QUOTE]
Do you mean with the engine stopped, or running?
In any case, misadjustment is very <span style="font-weight: bold">un</span>likely to be the cause of the problem. The cutout contacts are normally open when the engine is not running fast enough for the generator to put out at least 12v, so very likely that is the problem (lack of output) rather than misadjustment. Although they may drift over time, the adjustments don't just suddenly change on their own, unless something is broken.

Have you gone through the basic generator function test, where you remove the two wires from the control box, connect them together with a voltmeter to ground, and check for at least 20v by 2000 rpm? If the generator won't pass that, there is no point in messing with the control box until you get the generator repaired.

 

[JDstr4a]

32V @ 2k
D only a little over 3v steady up to 2k.
Going to have to stop 4 now and clean up. New garage floor to start tomorrow, which I've heard the last three weeks. I'll continue with the guide you provided and see where it takes me. thanks again!
JD

 

[JDstr4a]

back to the control box today. I started the regulator test procedure and have a quick question. When I went to jump A to A1 I noticed there are two BU wires on the A1 terminals. I check the generating and wiring system diagrams and they don't show.

Does anyone know what the second wire is for, and which one I should be jumping to the A wire for the test?

Thanks
JD

 

[TR3driver]

Assuming you mean brown with blue (which is usually abbreviated as NU), then Dan's schematic shows one wire to the horn fuse, and one to the ignition switch. The only black (B) wire should have no tracer and be only on the 'E' (for earth) terminal.

In any case, it won't hurt the test to remove and jumper both of the wires from A1. But the 'alternate' method of simply slipping a piece of heavy paper or thin cardboard into the cutout contacts is a lot easier and accomplishes the same goal.

PS, I'm not sure which diagram you are looking at, since both the TR4A owner's handbook and Dan's diagram show the two NU wires. In case you don't have it, Dan's diagram can be found at
https://www.advanceautowire.com/tr24a.pdf
(Scroll to the last page for the TR4A schematic)

 

[JDstr4a]

Thanks again Randall.I was referencing a cd I picked up when shopping for the tr, supposedly official for 4 and 4a. I checked the original owners manual and it does show a second connection for the horn, where the one on the cd shows the horn comming of a connection on the starter solenoid! It's possible my electrical problem may be associated with the horn circuits, since there was a wire which my mechanic had said was chewed through (mice nest), and i thought was cut, was repaired. I'm going to drive the wife to the store just to get a quick fix before I start again.

Thanks again
JD

 

[TR3driver]

I was referencing a cd I picked up when shopping for the tr, supposedly official for 4 and 4a.

Ah, sounds like an electronic version of the Bentley "Complete Official TR4 & TR4A". It unfortunately has several places where it doesn't mention the difference between the cars; including the fact that the 4A was negative ground, while the 4 was positive. Apparently the factory just felt it wasn't worth updating that portion of the manual.

The TR2-3B suffer from the same problem, the factory workshop manual was not updated in many respects, including the wiring diagram.

 

[JDstr4a]

I'm getting about 5V independent of rpm. It wont adjust. I pulled the box and still can't understand why the L formed by the armature and the tension spring is so askew, unless it was taken apart and put together wrong.The upper spring that the amature securing screws go through doesnt seem to be bent but when everthing is tightened it totally takes the voltage adjustment out of play. This spring piece is between an insulator on each side and rather than tear it all apart and try to rebend it, I think I'll just replace the whole module and save the original in my "parts drawer". Time to move on to the next challenge. Thanks for all the help.

JD

 

[JDstr4a]

Just for grins i went through all the physicall adjustments as best as i could and reinstalled everything. The contacts for both the voltage regulator and the cutout are closed with the ingine idiling and the amp guage shows +10 and the ignition light is out. I'm affraid to touch anything!

 

[TR3driver]

Sounds great, JD. Just keep an eye on the current when you start driving. If it stays above +20 amps for more than a few minutes, you'll want to turn the voltage adjustment (which is also the current adjustment) down a bit. Otherwise, too much current can overheat and ruin the generator.

Don't know about the later ones, but on the early control boxes, the difference between "too hot" and "too cold" is only a small fraction of a turn on the screw.

 

[JDstr4a]

Thanks, I still think I'm going to order a new module, since the voltage screw is all the way out already and not even touching the armature tension spring.I think I just got lucky on the manual adjustment, so I'll leave it for now and keep an eye on the amps. Thanks again for all your help!

JD

 

[Rrbbeerrttoo]

I may be late answering

My tr4A electrical diagram shows two brown/blue (NU) wires on ignition sw., contact 1. Fortunately is not that way, only one is on the ignition sw., and two on A1, same thing, just much easier to work with.

 

[Rrbbeerrttoo]

the NU wires go to ignition switch and to the headlights switch. Easy to know which is which, just pull one wire and test headlights. If still on, pull the other wire!

 

[JDstr4a]

Never did any further follow up. ! assumed the diagram link Randall provided which showed one to the horn for the 4A was correct since it matches the one in the original owners manual, but I'm having issues with the horn anyway and ordered a new horn brush along with the control module. The diagram I was initially using which I believe was of a 4 does show two connections on the ignition switch but a was pointed out was also positive ground. I'll give it a try today and let you know.

 

[JDstr4a]

verified the smaller NU from A1 to fuse before horn relay with ohmmeter.