# Air conditioning and heat

**URL:** <https://community.cartalk.com/t/air-conditioning-and-heat/70193>\
**Category:** Maintenance/Repairs\
**Tags:** envoyxl, gmc\
**Created:** [December 31, 2011, 12:38am UTC](https://community.cartalk.com/t/air-conditioning-and-heat/70193 "2011-12-31T00:38:19Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://community.cartalk.com/u/Gary_T)\
**Post date:** [December 31, 2011, 12:38am UTC](https://community.cartalk.com/t/air-conditioning-and-heat/70193/1 "2011-12-31T00:38:19Z")

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I have a 2003 GMC Envoy XL. There isn’t any heat or air conditioning coming out of the overhead vents. My mechanic tells me it is a control head module. I would like to try and fix this myself. I don’t know where this module is located on the vehicle. It seems I could just remove the defective one and replace it with a new part. If this is possible, I would appreciate any help or suggestions. Are these modules easy to find in part stores and how expensive is this part?

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [December 31, 2011, 5:50am UTC](https://community.cartalk.com/t/air-conditioning-and-heat/70193/2 "2011-12-31T05:50:52Z")

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The control head module is the component that is mounted in the dash with all the controls for the heating and air conditioning. So it’s a matter of removing the bezel from around the module, unplugging/removing the module, and reinstalling the replacement module.

Parts stores don’t sell these type of modules. This is a dealer only part. So you should be sitting down when they tell you the price. Unless you can find a functioning replacement module from a local auto recycler.

Tester

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**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\
**Post date:** [December 31, 2011, 10:13am UTC](https://community.cartalk.com/t/air-conditioning-and-heat/70193/3 "2011-12-31T10:13:01Z")

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For salvage yard parts, I have found this site to be more than useful: [http://car-part.com/](http://car-part.com/)