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Ignition Light Dead

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ColinGrey Colin Greyvensteyn
Cape Town, Western Cape, South Africa   ZAF
Hi All

Hoping someone can help me diagnose this.

My '57 TR3A sometimes goes dead while driving, once I stop I can turn the ignition on and off again but the red ignition light is dead, starter turns, lights go on etc but the car won't fire up. I fiddled around and it seems if I touch the contacts on the cutout inside the control box together the red ignition light goes on again and everything goes back to normal for a bit till the next time it does it. Fitted a new control box from Rimmer Bros but doing the same with the new one.

Anyone ever had this? I'm at my wits end!

Thanks
Colin



1957 Triumph TR3A
1967 Triumph Spitfire
1932 MG J2
1926 Lancia Lambda
1932 Austin 7 Ulster Replica
1971 Kawasaki H2
1976 Honda CB550
1962 Vespa Primavera

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Jacad Avatar
Jacad Gold Member Barry Shefner
Montreal, QC, Canada   CAN
1959 Triumph TR3A "Loose Wheels"
1976 Triumph TR6 "The Tweetster"
Colin,

I suspect that what you describe is being caused by an intermittent short somewhere along the white wire which comes off the keyswitch and travels to the ignition warning light as well as to the A3 terminal of the fusebox. Per the below diagram, if for some reason the A3 terminal isn't getting power, it would cause the coil not to spark so the engine would simply turn over and not fire. Lack of power on the white wire coming off the keyswitch would also disable the ignition warning light. First thing to do is check that all the white wires at the keyswitch terminal are well connected, perhaps the ones running to the ignition light and A3 fuse terminal are making intermittent contact. If that were the case, you would have headlight and the starter would turn over but no joy in actually starting. (Also likely no power to wipers and turn signals)



Barry
59 TR3A 0TS57675LO - "Loose Wheels"
76 TR6 CF54266U - "The Tweetster"
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)


Attachments:
Wiring Haynes.pdf    56.7 KB

TR3driver Randall Y
Confusion, Los Angeles, USA   USA
When this happens, does anything else controlled by the ignition switch work ? Ie does the fuel gauge come up when you turn the key on; turn signals work, brake lights work, etc ?

If not, I would tend to suspect the ignition switch itself, or a bad connection close to it. Carry along a test light or voltmeter/DMM with you, and next time it happens, check for power on the hot terminal of the coil and A3 on the fuse block.

The "ignition" light is really more of a generator indicator, it may or may not be a separate problem. But the cutout contacts have nothing to do with getting power to the coil, so I think that is a false lead. At worst, the bad connection (or broken wire) might be near the control box and so gets wiggled in the process of opening the box and touching the contacts. However, it's true that manually closing the cutout contacts would cause the light to come on, if the ignition switch is off (or not making contact).

Not sure if this will reduce confusion or make it worse : The diagram that Barry posted is for an earlier car. It is wrong in several areas for your car. But the ignition and charging circuits are substantially the same, so it serves the purpose. Just don't rely on it for wiring to the wipers, turn signals, brake lights and so on.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

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Jacad Avatar
Jacad Gold Member Barry Shefner
Montreal, QC, Canada   CAN
1959 Triumph TR3A "Loose Wheels"
1976 Triumph TR6 "The Tweetster"
Sometimes these wiring fault issues are quite maddening so a methodical approach is necessary to track down the cause. I had a similar issue with my TR6 this summer where sometimes when I turned the key the engine would turn over but there was no spark from the coil. Everything else had power and functioned normally. The problem occurred intermittently and I was certain it was a coil problem. After changing the coil twice and still no resolution I finally put a jumper wire between the battery and the coil and voila it started up and ran perfectly and detaching the jumper would immediately shut down the engine. Changed the keyswitch and solved the problem for good.

While the wiring diagrams are great for tracking the circuits, they depend on the wiring connections being as they appear on the schematic but after 60 years a lot of creative alterations may have been madesmiling smiley



Barry
59 TR3A 0TS57675LO - "Loose Wheels"
76 TR6 CF54266U - "The Tweetster"
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)

ColinGrey Colin Greyvensteyn
Cape Town, Western Cape, South Africa   ZAF
Hi All

Thanks so much for the input.

Had a look through all the advice.

Randal I checked on what you said, touching the contacts makes the red light come on, but may be because I was bumping some of the other wires. That was definitely a very misleading scenario and had me stumped.

@Barry also had a read through your suggestions thanks so much for them.

I think what is happening is that I had loose wiring in multiple places, in any event I went through the entire car and had a look through all and cleaned a lot of the contacts and the problem seems to have gone away only to be replaced with a new one.

The ignition light seems to be coming on slowly and at random while driving, and seems to take a lot of revs to go off. Would this look like a weak connection to the generator?

How does one measure if it's the generator that's the issue or perhaps the aforementioned pesky wiring?



1957 Triumph TR3A
1967 Triumph Spitfire
1932 MG J2
1926 Lancia Lambda
1932 Austin 7 Ulster Replica
1971 Kawasaki H2
1976 Honda CB550
1962 Vespa Primavera

TR3driver Randall Y
Confusion, Los Angeles, USA   USA
Hard to say from that description; the generator and control box are intimately linked so it could be a failure in either place or the wiring between them.

I would probably start by cleaning and adjusting the regulator contacts in the control box. The process is outlined in the workshop manual, although for some reason the procedures are given in reverse order. Cleaning requires a small amount of disassembly, which will require making the mechanical adjustment afterwards, which then requires checking the electrical adjustment.

If it still acts odd, then I would run through the tests given in
https://drive.google.com/open?id=0B2H2NJt34OffNTc3ODkwYzAtYjRlYS00NDNmLWI0YTYtNjY5ZjQxZTA2NGFm

FWIW, last time it happened to me, I eventually traced the problem to a bad connection deep inside the control box. The "shunt" coils on each relay have only one connecting wire, the other end is connected to a brass sleeve through the center of the coil which is then supposed to make contact with the steel center post. (This is the earlier control box, I don't know offhand if the later one is the same.) I found that the sleeve was not making good contact. When I went through my collection of "bad" control boxes, I found the same problem on several others, so it might be a relatively common problem. I was able to carefully disassemble and clean up the post & sleeve for a better connection; but it's kind of complicated and might not be for everybody. The result worked well for several years though, and was still working when the generator failed (the wrapping on the field coils had literally rotted and let one of the wires get tangled in the armature). At that point, I elected to set the original (!) generator and control box aside, and install a small alternator.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Jacad Avatar
Jacad Gold Member Barry Shefner
Montreal, QC, Canada   CAN
1959 Triumph TR3A "Loose Wheels"
1976 Triumph TR6 "The Tweetster"
Colin

Tackling a Lucas Prince of Darkness issue is generally not a straightforward task but that said IT CAN BE DONE! .... attached is the Lucas fault diagnostic booklet and Page 29 may be of help in sorting out the issue you describe as the ignition light intermittently going on and off. They mention a dirty cutout contact in the control box (as Randall already indicated above), high internal resistance in the ignition switch (not sure what that would entail) and loose/slipping fan belt as probable causes.



Barry
59 TR3A 0TS57675LO - "Loose Wheels"
76 TR6 CF54266U - "The Tweetster"
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)

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Attachments:
Lucas Fault.pdf    1.34 MB

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