I have a 2003 h2. A buddy of mine was driving it and all of a sudden half the guages dropped out like the truck was off. Temp controls went off radio off Windows stopped working and door locks. I went up there and pulled the cover to the ignition harness. At the ignition harness truck has all power where it's supposed to have it, ignitions, accessories, constant and start. Has anyone experienced this and have any input of where to start looking for the problem.

 

Check fuses first. If you have any aftermarket electronics installed, check the connections.

Take it in to Autozone for a free diagnostic code check.

 

Had an F250 do this when the alternator failed.

 

I would do wiggle test. Have someone watch the gauges and temp controls while you wiggle the wiring and see if you find a spot that will make it come back to life. I would start at the battery cables and underhood fuse box and work your way up inside.

 

I has same problem in 2007 H2. I was driving downt he road then I hear "ding ding ding" like the door opened, all gauges dropped, radio went off then said XM problem, but the vehicle could still be driven.
I brought it to a GM dealership and they said the "3rd party alarm system shortted out and caused the problem"
They pulled it out and all is back to normal
I think it was ~$300-400

 

I had a similar issue. Dealer said it was the rollover sensor that wasn't working properly. I all of a sudden lost power to half the dash. It happened intermittently. Then all of a sudden just returned to life. I bought a new sensor for if it happens again. Might have been a loose connection ?!

 

Make sure he didn't use the fuse panel above the left foot as a foot brace and damage the wires underneath. I was really bad for doing this when I first got my H2 and discovered that my heated seat issues were caused by this. I don't know how much of the dash runs thru this junction but its easy to get to and inspect.

Tim