[a.graham52]

the pcm comands the altinator to produce voltage. it can also very the ammount of amps/volts produced. such as under WOT it will command NO voltage leeving less strain on your engien. just like the a/c compressor wont work under WOT. that has nothing to do with your problem but just saying your pcm does have that kind of control. ill search GMSI and see if i can find anything sufull. i know theres a way to test the command circuit from the PCM. i velive i got my shit inline...