Originally Posted by Marys
I started tracing the wires and found what they called 80amp breakers in the wiring scheme but were basically 2 40amp fuses connected. I found one that had blown and replaced it but still no luck. I kept tracing and thought maybe the solenoid was broken but couldn't be sure so I called out a mobile tech. He predictably charged me to say it was the solenoid and that he didn't have and couldn't find the part. I found the part on Amazon and was waiting for it to arrive when the house magically came alive. I have no idea how it was raised from the dead, I just looked out the window and a light was on. Everything seems to be in working order so I guess I will just keep the spare part incase it stops working again.
There are usually those double breakers on both ends of the cables, especially from the engine charging so you may want to look for more of them in the same line. It is very possible for the unit to come back to life as these are auto resetting breakers. If the other was bad and current was above 40 amps the new one with it as soon as the battery charging or other loads got lower 40 amps the good one would reset and be good until the load went up again. This could happen is one breaker was bad on the other end of the cable. Or 190 Chevy had a pair one each end of the separator to battery line, one set by the separator under the hood and the other under the van at the battery tie point positive cable from the front.