Hey guys, on my 72 when the engine is running, the battery is reading 18 volts, which sounds to me like a good recipe for ruining a battery, I have read on other forums about the voltage regulator needing to be grounded to be functional and I was wondering if that could be my issue, and if it is, where might be the best place to ground it? Dumb question I know, but any help is greatly appreciated!
Is the 18 volts according to your gauge in the car or you checking it with a multi-meter?
THe voltage regulator on my 68 went a few years ago. Started off slowly, I noticed the gauge read a bit higher cruising one day. then next day at a car show, went to leave, the voltage gauge stayed at 40 volts after I started it. Had to disconnect the alternator for the drive home.
I would think the screws attaching the V/R to the firewall would be a good enough ground. Never had an issue with any of my Chargers in that aspect.
That reading came from my volt meter when touching the posts on the battery, I have had one battery go out and I cant help but think that had something to do with it. If the regulator being bolted to the firewall should do for a ground, what else could it be that's causing the battery to get that many volts if the regulator is new?
The regulator adjust field current by the voltage it reads inside its self. One of the two wires on the regulator (forget the wire color) is a keyed positive wire. with the engine running read the voltage between that wire and the regulator case. If the reading is the same as what you got at the battery try a new regulator. If it is more like 14 volts either the ground circuit to the regulator has high resistance or the keyed positive wire has high resistance.
Tim
Disconnect the green field wire from the alternator, if the battery voltage still runs high the alternator has an internal short. If the alternator output stops with the green wire disconnected, check the green wire for a short to ground between the alternator and the regulator. If the green wire checks OK, the regulator is bad.