I put a new alternator in my truck about 6 months ago (cheap autozone one). A few times the "gen" light has come on and the voltage has been low (~12V by the dash gauge). Everytime I've gotten to where I'm going and after restarting the truck is fine. The gen light has been on the past two times I've driven the truck and the voltage has read ~12v. Putting a meter on the battery today right after starting showed 8.5v for a few seconds then jumped right to 12.2 volts. It stayed there with a load on it (brights, defrost, int. light, etc..). It seems to me like the alt. is being regulated to maintain 12v.

So the question is, how can I test if it's the alt. or the pcm regulating the wrong voltage?

 

Just realized I put this in the wrong forum, any one got suggestions?