Another ALT thread
 

I'll be quick. Voltage off alt is 14.7, voltage at battery is 13.5. Any ideas?

Early 1991 w350 Cummins.

well our alts are not internally regulated to they pass through and external regulator, which probably why you see higher voltage at the alt than at the batt

Well, the battery blew up. Got a new battery and a new voltage regulator. Re did the alt wiring... Now I'm only getting 12.4 volts. Unless I ground out green wire on the voltage regulator. I do not understand the issues with this trucks charging systems, I've wire wheeled almost every ground. And added a few. No luck. Alt tested good. Here I am. Any pointers

search for a wiring diagram or get a chilton book retrace your wires