I had this exact problem last year while swapping an engine. I used 3 different alts and triple checked every connection, fuse, and ground. It stayed at 12 volts and slowly went down from there.
It turned out to be the volt/alt signal wire going into the gauge cluster. Somewhere down the line there was an open in the wire. I did some research into this and some people were saying that signal wire tells the regulator to ramp up the voltage to 13.5-14. Others say that's not the case. The FSM makes mention of the charge indicator circuit numerous times when diagnosing a suspected faulty alternator. I would look there.
|