Electrical Circus

Posted by TxGoat On 2024/6/25 13:05:48

My car began acting up last night. I pulled over to stop and the engine and lights died. The car restarted easily and ran fine for a mile or two, then tried to do it again downtown. I though perhaps the cut off switch in the ground cable was going out, since the car will run above idle with it off, but that didn't explain the instant re-start. I later noticed the car would sometimes die when I stepped on the brake. Once or twice, the ammeter fluttered crazily. I began to think maybe there was a short in the brake light wiring, or that the brake light load pulled the generator voltage low enough for the engine to die. What it proved to be was that the brake pedal arm under the floor was contacting the battery cable to the starter solenoid when I applied the brakes. This had rubbed the insulation on the cable, which sometimes allowed the pedal arm to short the cable to ground when the brakes were applied, and sometimes not. I moved the cable and taped it, and the problem is fixed, but now the voltage regulator appears to be overcharging. I put the battery on a charger, and will try it again later, but I suspect the intermittent short at the cable has damaged the regulator. The cut out function is working, and the points look like new. Putting a piece of paper between the regulator element points disables the generator and allows the cut out to release. The generator is now behaving like an unregulated 3 brush generator, where as before the regulator did a great job of properly regulating the charge rate, with the ammeter reading dropping to about 0 amps after a mile or two of driving.