Honolulu
Well-Known Member
Yesterday I hooked up jumper cables to the + and - leads of my '72 CS. Got in the car, turned the key and nothing - not even the dash lights. Under the hood was another matter, with a huge cloud of smoke. I hopped out and disconnected the jumper battery, pronto.
When the smoke cleared, about 4 inches of insulation had burned off the B+ wire at the back of the alternator. I don't believe the jumper cables were improperly connected. To me the smoke suggests a dead short in the alternator manifesting itself as too much current entering or exiting the B+ terminal, but I have to review the wiring diagram to get my head around it. Why did this happen? The alternator hadn't been spun in several years, so I took it out, cleaned it up a bit and shot some WD40 in the direction of the front bearing. I won't take it apart as the nut holding the fan looks really tight, and after some lube it spins nicely with no dry sound from the bearing. I took the voltage regulator off the alternator for a look-see and cleaned the contacts, which didn't look that bad.
I'll take the alternator to a shop and have it tested, but in the meantime can anyone suggest a failure mode that would produce this? I have some fried wiring to trace and replace. It's been a long time since I changed out the auto trans for a four-speed, then a five-speed. The car had been running okay when parked, so the smoke is somehow a product of a long layup.
TIA
Charlie
When the smoke cleared, about 4 inches of insulation had burned off the B+ wire at the back of the alternator. I don't believe the jumper cables were improperly connected. To me the smoke suggests a dead short in the alternator manifesting itself as too much current entering or exiting the B+ terminal, but I have to review the wiring diagram to get my head around it. Why did this happen? The alternator hadn't been spun in several years, so I took it out, cleaned it up a bit and shot some WD40 in the direction of the front bearing. I won't take it apart as the nut holding the fan looks really tight, and after some lube it spins nicely with no dry sound from the bearing. I took the voltage regulator off the alternator for a look-see and cleaned the contacts, which didn't look that bad.
I'll take the alternator to a shop and have it tested, but in the meantime can anyone suggest a failure mode that would produce this? I have some fried wiring to trace and replace. It's been a long time since I changed out the auto trans for a four-speed, then a five-speed. The car had been running okay when parked, so the smoke is somehow a product of a long layup.
TIA
Charlie