Just FYI, even though it's too cold to be running AC, it still runs when you least expect it to. Usually, when you have the climate controls set to defrost, the compressor will run. This has two main reasons: 1. Running the compressor will pull the moisture out of the air flow. 2. it circulates the coolant and oil to keep things from getting seized up.

Call me what you will, but I'm a firm believer that a GM dealer will screw you quicker than a Ford or Dodge dealer.

AND Just why is she driving your truck? Hell, I'd take the 460 first. We have one that gets all of 5 MPG unloaded, but people get out of my way too. The only reason its so high compared to most is the fact that it has been chipped and runs on 92 with enough octane booster to get it to 103. (and it's a 6 speed) Mmm... Flat bed dually 2wd.. Fun.

 

shiloh you got a pm in your inbox

Chris..you need to get that dang things fixed and ***** it up..

 

+1~~~~~

 

The diode mentioned keeps the fan from becoming a generator and feeding current back thru the system which will do stupid stuff like keep things turned on when they shouldn't be. They also have them on 2 speed fans to separate the windings in the motor so the unused speed doesn't send voltage back into the system.
The price was dealership High (Obama Motors owes the Gov a lot of money!!) but the diagnosis was probably correct. (Just because a fan worked doesn't mean it didn't have a short or bad bearing)
Yes in cool temps the a/c compressor and fan will work in any defrost mode. Once it gets down in the lower 20"s and less it may not. The refrigerant pressure drops too low to make the pressure switch.