Sounds like you are getting closer.
The problem should have to fulfill two requirements ... something electrical in contact with the coolant .. and isolated from ground. Anything that fulfills those two and is energized all the time.
I was thinking about the electric fans too. The radiator is probably isolated from ground, rubber mounts, rubber hoses ... if the fan mounts are metal in contact with the radiator and there is any kind of voltage leakage ... could cause electrolysis in the radiator. But I don't imagine there is any power running the fans with the ignition off.
Maybe something touching the heater core .. unlikely.
Does it have an aftermarket electric temp gauge?
Volt Ohm meter might help. Put one lead on the neg. side of battery, dip the other in the coolant in the radiator without touching anything and see if there is any voltage showing (with the ignition off).
|