A/C problem?

[ripracine]

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.

[THEFERMANATOR]

Sounds like somebody flashed in the wrong operating system into the ECM. On 03-05 trucks the operating system in teh ECM is specific to the installed features of that truck, so all tunes should be built off of teh origanal tune file. Sometimes peopel will flash in a differrent operating system that has differrent features which will make it so that features like your A/C, cruise control, and sometimes even power windows go haywire. You need to find out who tuned it origanally, or have it flashed at teh dealer to the stock tune to make sure it isn't the operating system in teh ECM that is your problem.