I recently purchased a 1998 Sierra 1500 V6 and yesterday i began having a/c problems. The a/c now only blows cold when either in the defrost or the feet/defrost settings, and will only blow air through the feet vents no matter which vent setting you select whenever the a/c is turned on. When you turn the a/c and circulate buttons off all the other vents operate normally. I belive the problem is most likely a short in one of the a/c controls, such as one of the switches or dials but figured i would ask around before I spent any money to fix something that might not be broken. If anyone knows what might be causing the problem any help would be appreciated. Thank You.


6-15 : Replaced a/c control panel and it fixed the problem.

if the person before you had an aftermarket head unit installed and they had a sub system, they probably dropped a rca cable down into the ac motherboard and shorted the circuit, beleive me thats the problem, I've replaced 3 on my truck.