So I've been having an intermitent problem with my charging system. Started in December voltage gage drop off and light came on. Drove it for about 2 hours and it subsequently ran out of juice, but just as it was dying it came back to life with full charging, headlights, and power. So that lead me to believe it was more than likely the regulator in the alternator. Nope, bench tested the alternator and it was good. Problem was gone so I just let it be. Happened multiple other times but always the charging system would eventually come back to life.
...Until monday when it ran out of juice again. Bench tested the alternator and again it was good. Checked my contuity across both generator field and source wires from their respective PCM pin plugs to alternator. Contuity exists, so no broken wires. Charging system didnt work last night, did work this morning, then quit again on me this afternoon. The intermitance of the problem leads me to beileve my PCM isn't functioning properly. Is there any other thing to check or ways to determine if the PCM is faulty?
Thanks
Cody

 

I just cured a similar problem that turned out to be a short in the black #4 cable from the alternator to the power (fuse) centre. Put in a new cable and all the gremlins dissapeared.