i have an '03 Chevy 2500HD Silverado, with automatic climate control. It had a 5 position EFI Live tuner when I bought it. The A/C hasn't worked since I bought the truck, and the dealer has tested/changed everything they can think of, with no luck. I have narrowed it down to the A/C relay not getting a signal (if I jump the relay over, the A/C pump kicks on).
Is it possible that the tuner is somehow messing with the climate control? Or anything esle that would cause the A/c not to function?
Any advice anyone can offer would be greatly appreciated.