My coworker brought me his 2007 Colorado he had bought for his son and he has been trying to solve an AC blower motor issue of intermittent operation. he had replaced the resistor and the wire connector for it. he replaced the blower motor and replaced the blower motor harness. The blower motor worked for awhile and then quit again. In desperation he replaced the AC control head on the dash, but no blower motor. Given all this info, I decided there must be a problem with the feed wire between the fuse box and the plug at the motor. The AC blower motor fuse was good with proper voltage in and out. I removed the glove box and unplugged the new blower motor harness and using a volt/ohm meter found that there was only 7 volts feeding the brown wire for the blower motor, not enough to operate it. Under the hood at the fuse/rely box, I checked for proper voltage at the blower relay terminals and I removed the blower relay, installed a jumper wire and still got only 7 volts at the blower plug. So, I ran a new 14 gage wire from the blower motor feed at the fuse in the fuse box to the blower motor plug by passing the factory wire. this brought 12.5 volts to the blower motor and it has worked fine now for two weeks. I could not see where any of the factory wire had been chopped, cut or compromised in any way, so the 7 volts I found at the blower motor plug is unexplained. I just wanted to pass this on to anyone having similar issues.