i have a 1978 or 79 Toyota chinook newport (and an 1969 fj55 landcrusier.)
my charge light is currently on inside the pickup/chinook and overcharging to 16V+ when rpms increase, idling at around 13.5. when the charge light first came on and i starting exploring it i found water in the boot on the alternator...i removed the alternator had it bench tested at advanced and they said it was good. so i just replaced the voltage regulator but still no charge, so i had that VR swapped under warranty with no luck in charging the system.
took it to a shop here in pittsburgh and they put new B+ wires and a new voltage regulator and charged me $406! and it started over charging then. i took it upon myself to replace the alternator (http://shop.advanceautoparts.com/p/bosch-alternator-remanufactured-50-amps-al223x/26942673-P?navigationPath=L1
*14920%7CL2*14999%7CL3*15587) thinking the diodes were just bad somehow and it's still overcharging. then i took it back to the shop and they said they replaced the VR again under warranty as it was supposedly ok when it left them the first time but i get one replacement part and they were done. its still overcharging and they don't know why. so thats where i'm at. All new voltage regulators were 6 bladed green-plug types.
ive had the battery tested at both autozone and advancedauto and the shop probably tested it too at least they better after all the money i paid them, damn. ill take it in again and have the battery tested to see if its bad. i see now that they boiled it over at some point. it was fairly new but from walmart, so?? is there a way voltage can be fedback through possible wires touching or do diodes fail in the cluster maybe? i cant find a charge light relay and don't think it exists in a 1978?? should i replace the instrument cluster to fix the charge light and overcharging issue?
any help is greatly appreciated as its going on 2.5 months now. ugh
ive read about gm 1 wire conversions, i'm just deep into this now yah know.