2005 GMC Envoy 4WD 4.2L. Customer states the vehicles blower motor doesn't work on any speeds, the a/c doesn't work at all, and the sunroof doesn't work. I took the vehicle in at the end of the day so I did a little diagnosis but not much. Just wanted to see if there was any usual problems with these vehicles? As far as checking the blower motor, I removed it from the vehicle and hooked it straight up to the battery and it worked fine. Put it back in the vehicle. Checked voltage. It had i think 10.4 volts at the connector. The diag chart said 10-14 is acceptable. I started the vehicle and it worked on high only. Turned off the vehicle and started it again and it worked on low. Each time I started the vehicle, it was on a different speed. When i look at the Tech 2, when I push all the buttons (fan up, fan down, ect), the Tech 2 shows that its reading me pushing the button. I can command the a/c on thru the Tech 2 and it comes on, but when I push the a/c button on the dash, it doesn't work. Are these vehicles bad about the HVAC modules in the dash going bad? As far as the sunroof goes, it will not work in any direction. Haven't really got to it yet. Like I said, I'm gonna work on it a little more tomorrow, but I just wanted to see if there were any common problems related to these. Thanks