I already changed the belt once at 90k and a few k later the light started coming on again is the alternator bad or the battery, did any body else have this problem. help, its a good excuse to by new stuff.

 

alt is my guess, do u have a tune? or a newer pcm??

 

no tune or pcm all stock just exhaust

 

sounds like the alternator, test the alternaor you should get something like 14 volts or higher, if you have 14 plus volts at the alt, then its prolly the battery good luck!!

 

Get a handheld scanner, or go to Autozone to get them to tell you what code it's throwing. My '02 Yukon gets the P1637 code, and GMSM suggests checking all the common things. I replaced the alt, battery & belts, but still comes on. GMSM suggests checking the alt's terminal connections for proper contact. Got a friend who'e ASE certified, and he mentioned changing the wire that connects to the alt, but I don't feel like doing that. From what he says, it's the PCM telling you that the alt's producing current outside it's suggested operating range (more or less). As long as it produces 14+ V, I'm okay with that light flashing on & off every blue moon.

 

Thanks guys for the info

 

I got this code a few days ago. I kept getting the battery light flashing when the engine is off and I'm listening to the radio. I couldn't find any loose connections. I reset the code. I guess I have to wait awhile and see if it comes back. The code was P1637 Generator-L-Terminal Circuit. Anybody know what this refers to?