2005-2007 H2 Hummer Blower Motor Inop / Will Not Shut Off / Dead Battery - keywords AC HVAC water Leak

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some customers may state that the front HVAC blower motor will not shut off or is in-operative. On initial Inspection, you may notice that the front blower motor or the blower motor module has signs of water intrusion. This issue may be the result of the right side sunroof drain tube being mis-routed and laying on top of the windshield wiper washer hose. This could cause the water to drain out of the sunroof drain hose and follow the washer hose into the HVAC air inlet duct. If this was to occur, water would enter into the blower motor and under certain condition could freeze. This would cause a linear power module (Blower Motor Module) failure and could cause power to be applied to the blower motor all the time resulting in a dead battery.

If the Blower Motor or Linear Power module has signs of water intrusion or the Blower Motor will not shut off. Remove the front wiper arms and front cowl assembly. Then remove the plastic access panel that is located on the passenger's side of the vehicle and inspect the sunroof drain hose. Make sure that the sunroof drain hose is routed downwards and away from the washer pump hose and the HVAC Air Inlet Duct

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.