TR2/3/3A electronic distributor problem

[TRusty]

My (brand name 1-2-3) distributor has failed three times in 4000 kilometers. The manufacturer of distributor thinks the failures are caused by my alternator. Can anyone explain what might be happening?

I have electric fan, high torque starter, alternator, halogen headlights, high power coil, heated seats,
electric fuel pump all wired in by me. Everything works perfectly, HOWEVER, after all was hooked up, engine continued to run with key off. Several forums said I should wire in a rectifier diode at wire coming from the alternator. I did, it worked. I have explained that to two different auto electricians, both said to leave it in, that it could cause no problem. The only difference that I can see is that the ignition warning light stays on. No, the light is not grounded.

Thanks, Paul

 

[TR3driver]

Are you saying that the ignition lamp stays on now? Or that it stayed on before you added the rectifier?

I can't see how the alternator could be related to the distributor failures, unless it was somehow putting out high voltage spikes under some circumstances. Perhaps an intermittent connection somewhere that momentarily disconnects the alternator from the battery (and then reconnects again). I once had a somewhat similar problem caused by the ground strap (on a non-Triumph) being loose at the engine. It would spot-weld during cranking, but then break loose and dance around while driving.

When the alternator is working hard, it takes some time for the regulator to shut it down if the load (battery) is suddenly removed. This condition is known as "load dump", and can cause voltage spikes over 100 volts!
https://en.wikipedia.org/wiki/Load_dump

 

[TuffTR250]

May be totally unrelated, however I had an old Oldsmobile with and EFI module in the distributor. Over and over it kept blowing the EFI module leaving me stranded. All the mechanics and auto electric places I talked to could not tell my what the problem was. I finally replaced the alternator and never had another EFI module failure. I suspect the alternator was spiking and blowing the EFI modules. I recommend that you replace the alternator. Good luck!
Regards,
Bob

 

[TRusty]

Randall, Bob,I have done something wrong again and it looks as if I have erased another lengthy reply. This time, vrry short, the problem was a broken wire, neatly consealed by shrink tubing, leading to distributor. It's been running great but will give it another run tomorrow when sun is shining. Thanks again, I really appreciated the quick replies. Paul