2003 Hummer H2 V8 All Wheel Drive Automatic 71 000 miles
I have 2003 H2 and its water damaged. None of the gauges are working exept for their ligths. The front window power is not working either. I have grounded the heater from the body in order for it to work. The controls for the heater show that they are working but we can't control the level of how much heat we need. I already installed a new module but it still the same. It can be turned on/off by grounding the heater. When I ground the wire, the heater just turns on and stays on one level. I can change heat from windshield to floor or front but can't control how high I need the heat to be. I already installed the body module.
This may be a ground problem. Make sure you have a good ground that goes from the battery to engine, engine to body and battery to body. Also see if there are any grounds under the dash that are dirty, especially since this has been undrwater. As far as guages go you may have to replace the circuit board or get the whole panel redone to make it work.