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

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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?
 
doughairfield said:
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.
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Oops! :wink:

doughairfield said:
Is it possible that the flashing light light, though should be the red one is indicating an over charging?
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I'd think it might be indicating that the regulator is cutting in and out?
 
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?
 
doughairfield said:
Is it possible that the flashing light light, though should be the red one is indicating an over charging?
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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.
 
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 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.
 
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?
 
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.
 
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?
 
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.
 
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.
 
doughairfield said:
Will I need to disconnect the battery before testing the resister and moving the armature on the VR?
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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.
 
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.
 
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.
 
hum, well I'm kind of at a loss as to where to go now with this problem.
 
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.
 
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?
 
I don't know if you have a copy of the wiring diagram, so here's one from Advance Auto Wire. 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.
 
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.
 
martx-5 said:
and a brown/yellow on the other side going to the "D" terminal of the control box (voltage regulator).
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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.


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