# Air Conditioner **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [May 21, 2008, 5:57pm UTC](https://community.cartalk.com/t/air-conditioner/14295 "2008-05-21T17:57:20Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![huisache](https://avatars.discourse-cdn.com/v4/letter/h/ecd19e/32.png) [@huisache](https://community.cartalk.com/u/huisache)\ **Post date:** [May 21, 2008, 5:57pm UTC](https://community.cartalk.com/t/air-conditioner/14295/1 "2008-05-21T17:57:20Z")
I have a 2004 GMC Pick Up and the A/C changes to heat when I’m driving down the highway. If I stop, turn off the engine and re-start it the A/C is OK again. This happens periodically and without warning. What could be the problem? My dealer is baffled. ---
**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\ **Post date:** [May 21, 2008, 8:07pm UTC](https://community.cartalk.com/t/air-conditioner/14295/2 "2008-05-21T20:07:09Z")
Since I doubt if it is still under warranty I would suggest taking it to a A/C shop, not the dealer. There are a number of possible issues and a good A/C shop is most likely to find it. ---
**Author:** ![crankwalk5](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@crankwalk5](https://community.cartalk.com/u/crankwalk5)\ **Post date:** [May 22, 2008, 1:40am UTC](https://community.cartalk.com/t/air-conditioner/14295/3 "2008-05-22T01:40:12Z")
if your dealer is baffeld at that common issue (which I doubt) find a new dealer.