HummerZ, I didn't see your message before I sent mine.

My alternator voltage is the same as the battery voltage. I've checked the "mega fuse" for continuity (good), and connections, and that is where I'm checking my voltage. I'm going to start removing things to get at the alternator better.

 

Removing #32 bypasses the GBCM. Alternator would then max output, check voltage at alternator running. If you are confident the wiring/connectors to the alternator and battery are good. REPLACE THE ALTERNATOR.

 

Got it. Thanks for clarifying what fuse 32 does and what you were after. I agree with you that it's probably the alternator now - I feel more confident.

I'll let you know how it comes out.

 

GBCM= voltage regulator. You lost me when you posted the voltage came back on your original post, the alternator had one last breath? RIP alternator you survived 190k. Btw, make sure your battery is fully charged and tested before you start up after alternator replacement. GL

 

Alternator replaced. Good voltage so far! Hummerz, I agree, it threw me as well when it started charging again. Never had an alternator do quite that. I appreciate the help tonight.
FYI, I took it out through the top based on another thread. It really wasn't that difficult. Definitely take the time to take the fan and shroud off though.

By the way, my radio problem has not gone away, but I'm guessing these things are not related, and I'll start a new thread if I can't figure it out. I still think the On-Star has something to do with it. I can't find a fuse for it to try to disable it.

Oh, one last thing - yes, I charged the battery while I was replacing the alternator. Started up on it's own power.

Thanks again.


Ryan