I've had my 2003 H2 for about 8 years now, and have experienced some strange issues like air bags deploying while I was driving I think the strange issues were mostly due to leaks from the roof lights. I've siliconed them but maybe due for a refresh.

This issue may be related to leaks, but wanted to see if anyone else had this happen...

I got in the truck yesterday and I couldn't press the shifter button. And also, the windows, door locks, power mirrors, and wipers were not working.

I got back in the truck today, to start troubleshooting further - making a list of things that were not working. I was thinking fuse, or some other wiring issue... All of the sudden, it all started working again.

The only thing out of the ordinary is the truck was in a parking garage all week and I gave the attendant the key only (not the fob also). I have no idea is this has anything to do with it, but thought it was worth mentioning...

 

Any evidence of mice? I just got my H2 last week and it had been sitting for sometime, and electrical seemed a little weird, but the more I drive it the better it seems to get, Im not a lot of help, im new to Hummer

 

the air bag module is located under the drivers door and can get soaked with water coming down the driver side A pillar and get damaged.
you might also need to check the grounding point under the truck near the A pillar on the body mount for corrosion.

 

Just my $.02 Wort Here...But the battery if old or corroded terminals or a Bad Ground from the battery can play hell on the whole electrical system and puters. Even if it's a new battery. Once you have variation in voltage you can **** off allot of the control modules. Also for chits and giggles I would test the output of the Alternator at idol and make sure it's putting out at least 13-14 volts plus.

The ECM controls the alternator. No more voltage regulators.

 

On GMS H2 all Harness goes to modules come togueter at a Serial port SP20. Check that out,