Three problems related to blower have been reported for the 2005 GMC Canyon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 GMC Canyon based on all problems reported for the 2005 Canyon.
Air conditioning fan abruptly stopped working on all fan speeds except "4", the highest position. Checked internet for possible solutions and found that there have been numerous failures exactly like mine. All involved the "blower motor resistor assembly, connector and/or wiring harness" shorting out. Scortching the connectors, resistor assembly and causing the plastic to melt/burn. Gm parts at local dealership had replacement parts and I was able to resolve the problem. Speaking a gm service advisor, he confirmed that there are numerous repair problems with these parts on the GMC Canyon/ Chevrolet colorado 2004-2007. But no explanation for why they are failing. Numerous internet reports with photo's showing damage and explaining problem most requiring multiple or repeated repairs. Old parts are available.
My air conditioning suddenly stopped working except for on 4 (the highest speed) dealership told me it was the"blower motor resistor assembly, they repaired it and within 10 days the same problem occurred. They had to keep my truck overnight each time so they could order the part. I had to pay $200 to get this repair done.
The contact owns a 2005 Toyota sierra. The contact stated that the air conditioner and heater would only worked when the setting was on high. The dealer diagnosed that the blower motor resister was defective. The manufacturer was notified and did not assist the contact with the failure. The failure mileage was 20,000.