Hi all. I am new to Hummers and the forum.

I purchased a 2008 H3 Alpha with the 5.3. The power windows and the power door locks will not work. The person who drove it last night said the head lights did not work and that the radio/navigation system was acting up as well. The lights are working now.

The truck seems to not be holding a battery charge as the engine turns over slowly initially, but picks up and starts after a brief labored start.

The left rear window will operate as it should, but only with the door switch. None of the other windows work with the master window switch on the driver's door or their respective door switches. The door locks will not operate with any of the switches. The key fob will not lock or unlock the doors, but the chirp indicating the doors have locked works.

I haven't driven the truck much, but the issues appear to be intermittent and some may be due to operator error?

Could it be the body control module?

The truck has a 3" lift and the prior owner installed under body LEDs.

The truck is in otherwise great shape.

Please help. Thank you.

 

The truck has 115K miles. And the rear window switch that does work is broken-the top part of the switch has separated from the bottom portion of the switch-but it does operate the window.

 

Does it have a sunroof? Are the drains plugged up. If so, your BCM likely got thrashed getting wet. See Finally, a fix for clogged sunroof drain tubes

Do the fix ASAP, then look into inspecting the BCM for water intrusion/corrosion.

 

I does have a sunroof.

Thank you for your reply.

 

H3s are notoriously sensitive to voltage variations, causing all sorts of weird behaviors. Do you have the stock battery cable terminals? GET RID OF THEM, NOW, NOT LATER! Cut them off and replace them with some Stingers or similar. (got your back, Doc!) Then, check your voltage while running; should be at least 13.5v or above.

 

this is for an 07 but should be similar troubleshooting procedures. its a long read.
https://schwarttzy.com/wp-content/up...dows-1-4-1.pdf