My 2005 Silverado is driving me nuts in this heat. The ac blows great, until I get over twenty miles an hour, then it shuts right off. It could sit all day idling, and be cold as ice. But once I drive over twenty, wham, it stops blowing cold air. HELP!”
I’ve seen that happen before. They’ve had nothing but problems with the control heads for the AC and Heating system on those trucks. The one I fixed just needed a new control head, and they had plenty for sale at the dealer (since they break down so much.) Somehow the computer circuits inside the control head just break down a lot and then just turn the AC off. They can break at any time, but I have seen them cut off at certain speeds only in those trucks, which seems pretty weird but what do you expect with computers?