2003 Yukon XL, 158,000 miles, 5.3L V-8. 4wd. Has the digital control deck for climate control with a knob on both sides for Driver vs Passenger cooling/heating.
I live in the country and a wood rat built a nest under the hood at the passenger side firewall. I've attached photos. There was one wire set that was damaged, as pictured, and I repaired it and reconnected.
I got in the SUV other morning and when I started it the blower motor turned on full blast and would not turn off with the climate controls. I turned off the vehicle and removed key and the blower stayed on High, even with the car off. I removed the fuse from the interior fuse box (10 amp I think) and it remained on. So I disconnected the negative battery terminal to make it stop, which worked. But each time I reconnected the battery terminal it would come back on "High" speed and not go off again. So I figured out there is a 40amp fuse under the hood that also controls the front blower. When I removed that fuse it will stop, but I don't have any interior air circulation by forced air if I do that.
At first I thought the two wires that the rat chewed off was making a strange control circuit and forcing the fan to turn on High and stay on. But I repaired the wire and it still is staying on if the batter is connected.
I've searched online and found some Sierra truck owners with similar problem but they have a different climate Control Deck than I do. I've got the crappy all digital deck, with knobs that get dusty and won't turn up or down. Some folks were saying a resistor goes bad, thats connected to the blower motor, which is down by the front passenger's feet. However the same people said that removing the 40 amp underhood fuse solves the on "high" problem and allows the driver to still control Low through Medium speeds (1 through 4 on Sierra from what I gather). This doesn't seem to work for me at all, plus the passenger front foot area looks different than the Sierra, and the blower motor resister board looks totally different, if it is the same thing to begin with.
Anyway, does anyone have the same issue or know where to look next for the cause of my blower motor staying on High full time, car on or off? I'm unsure if the rat has chewed something else, but I don't see anything that indicates this. Furthermore, what can a rat chew that would cause the blower to stay on "high" with the ignition and vehicle turned off? That doesn't make sense, so I'm thinking some electrical device has crapped out and is causing this. Maybe consequential from the rat chewing the wires, or something totally unrelated.
Thanks!
andy
I live in the country and a wood rat built a nest under the hood at the passenger side firewall. I've attached photos. There was one wire set that was damaged, as pictured, and I repaired it and reconnected.
I got in the SUV other morning and when I started it the blower motor turned on full blast and would not turn off with the climate controls. I turned off the vehicle and removed key and the blower stayed on High, even with the car off. I removed the fuse from the interior fuse box (10 amp I think) and it remained on. So I disconnected the negative battery terminal to make it stop, which worked. But each time I reconnected the battery terminal it would come back on "High" speed and not go off again. So I figured out there is a 40amp fuse under the hood that also controls the front blower. When I removed that fuse it will stop, but I don't have any interior air circulation by forced air if I do that.
At first I thought the two wires that the rat chewed off was making a strange control circuit and forcing the fan to turn on High and stay on. But I repaired the wire and it still is staying on if the batter is connected.
I've searched online and found some Sierra truck owners with similar problem but they have a different climate Control Deck than I do. I've got the crappy all digital deck, with knobs that get dusty and won't turn up or down. Some folks were saying a resistor goes bad, thats connected to the blower motor, which is down by the front passenger's feet. However the same people said that removing the 40 amp underhood fuse solves the on "high" problem and allows the driver to still control Low through Medium speeds (1 through 4 on Sierra from what I gather). This doesn't seem to work for me at all, plus the passenger front foot area looks different than the Sierra, and the blower motor resister board looks totally different, if it is the same thing to begin with.
Anyway, does anyone have the same issue or know where to look next for the cause of my blower motor staying on High full time, car on or off? I'm unsure if the rat has chewed something else, but I don't see anything that indicates this. Furthermore, what can a rat chew that would cause the blower to stay on "high" with the ignition and vehicle turned off? That doesn't make sense, so I'm thinking some electrical device has crapped out and is causing this. Maybe consequential from the rat chewing the wires, or something totally unrelated.
Thanks!
andy
