I have a 1983 Dodge W150 that has a problem. It stops running with the electrical system completely shut down. If the battery is taken out of the system, and then reconnected, it starts and runs fine. Some history: a trailer brake control was installed a few years ago. Where the wire ran from the battery through the firewall, the insulation chafed and eventually shorted out. The fuseable links were burned out. I disconnected the brake control from the battery and replaced the fuseable links with a fuse block. The truck ran fine for 18 months. It has stopped twice in the last couple of days. Apparently something like a circuit breaker is tripping and then resetting when the battery is disconnected and then reconnected. My questions are 1) what is the breaker likely to be intended to protect, 2) where would the breaker be found, and 3) what is the likely cause of the breaker tripping (a short, but in what system)? Thanks for any suggestions.
I doubt there is a circuit breaker causing this trouble since they reset be themselves usually. The trouble you describe seems more like a problem with a solid state device or electronic module. You say the electrical power drops out. You need to to do some testing starting at the fuses under the hood to see where power is being disrupted at. I doubt the trouble is with those fuses but there may be a faulty connection to them somewhere under the hood. Using at least a test light probe will show where power is getting to and isn’t while the trouble is happening. If power to the interior accessories is going out also and you don’t find a problem under the hood then the ignition switch my be at fault. You should have power getting to the dash fuses with the switch ON.
The most outrageous efforts to patch up electrical problems have been seen on Dodges from the early 80s. I have ripped out many yards of patched in wires and found that often the problem at the bottom of the cluster was the wiring manifold a foot or so from the battery. The fusible links that merge and connect to the battery there are prone to intermittent loss of continuity and when tested with a meter or light they check out OK but fail when any substantial current is needed.
This is a somewhat difficult problem to diagnose because it happens so infrequently. When it happens, turning the ignition does not cause any clicking or any lights in the dash to come on. When the failure occurs, its usually somewhere inconvenient (last two times, my wife had driven the trunk to work in a snowstorm, and I got stranded at the PO in several inches of melting slush with 3 dogs in the front seat, not an aid to extended analysis). What I suspect may be happening is the trailer brake control, while disconnected from the battery terminals, is still tied into the system somewhere. I’m going to try and test this by attempting to cause a failure in my driveway by stomping on the brakes at low speed (high speed being inadviseable with the snow and ice). If I can reproduce the failure, then I can start testing hypotheses. By the way, I’ve done continuity testing on the wiring I replaced when the fusible links were damaged. I replaced the entire set of fusible links with a fuse block secured to the truck body under the hood with a weatherproof cover.
The trouble you describe is due to a lack of power either before the ignition switch, with the ignition switch, or right after it. The trailer connection can’t cause this kind of trouble since it doesn’t supply power to the areas you mention, like the dash . It is just another branch off the battery. It would be interesting to know if the brake lights worked while the trouble happens since they are tied to power close to the battery. If they fail to work then there may be a faulty wire from the battery to the fuses under the hood or perhaps even the battery has a problem, though that isn’t real likely.
Power from the battery goes though a wire (possibly a fusible link in this case, which may be faulty), to the fuse panel under the hood, then to the ignition switch and the fuse panel in the dash. Your problem is either with the ignition switch or in the wire distribution before it. Moving wire harnesses around by hand may show up the trouble.
I had a late 70’s dodge truck that did the same thing. Just under the dash on left hand side of steering wheel was what I think is a voltage regulator. I felt it and it was HOT. I replaced it and problem fixed.
This was many yrs ago so memory a little sketchy.