Allegro Electrical Troubleshooting

[Daniel Long]

I like to get some input on some electrical issues I'm having, specific to the headlights and signals. When the headlights are off, the signals work as they should (except my transmission temp light blinks when I use the turn signals but I bet I know what's causing that!!). The issue is when the headlights are on the right blinker indicator stays lit and you can't get the right turn signal to blink. Left is good.

Any insight as to what may be causing this? I have access to the fuse block so I'm going to check a couple of things. My suspicion is that something is either not wired correctly from the headlight switch back to the main fuse block or crossed on the signal circuit.

Suggestions will be welcomed.

[Russell E Johnson]

Hi Daniel, I had the same problem with my Southwind (AKA the MMP). It turned out that the ground on the right front turn signal was all rusted up and not making contact. I spliced into the ground wire and added an additional ground wire and that cleared up the headlight/turn signal problem. I then developed the same problem on the left turn signal but that turned out to be the bulb going bad. When the element burned out, the top element fell against the lower element and so was running the electrical path with the running lights. New bulb and all is copacetic again. When you are chasing electrical problems on these classics I think you will find that the majority of the problems will be related to bad grounds. That has been my experience, YMMV. Good luck.

[Daniel Long]

Thanks, yes the grounds on any old vehicle seem to be the "go to" spot for fixing the electrical gremlins. Hoping the weather holds out after work and I can spend some time with my wire spools, clips and other bits to get this working right.

I gotta say, the LH1 ('77 Dodge Tioga) had many of the same issues. It was fine in the daytime, or at least I thought so! Come evening and the lights were turned on and then after a while the signals would not work right, then the gauges (you can tell that now the alternator set up was going) and then all sorts of crazy stuff would stop working. Not fun hundreds of miles away and in the dark.

So this time I'm triple checking all the systems, added the gauges and making sure with several short trips in the state that everything is worked out.