# 2004 suburban air cond on driver side goes to heat while driving

**URL:** <https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765>\
**Category:** Maintenance/Repairs\
**Created:** [July 15, 2007, 9:19pm UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765 "2007-07-15T21:19:04Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![bbrin1](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@bbrin1](https://community.cartalk.com/u/bbrin1)\
**Post date:** [July 15, 2007, 9:19pm UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765/1 "2007-07-15T21:19:04Z")

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Passenger side stays cold as does rear unit. Have to stop, cut off engine wait 3-5 seconds and start again. everything is fine for about 30 minutes of driving.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 15, 2007, 9:32pm UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765/2 "2007-07-15T21:32:03Z")

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Not familiar with zone question. both front thermos are set to same setting. Only driver side dash outlets are putting out very hot air.  
Thanks

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**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:** [July 15, 2007, 10:47pm UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765/3 "2007-07-15T22:47:31Z")

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Assuming you do not have separate controls for the driver side and the passenger side, then my guess is it is a vacuum problem. You may have a vacuum leak or just weak vacuum. On most cars the heater controls are managed with vacuum. A small leak can cause what you describe. Let me guess. Right before you notice the heat, you accelerated, like maybe from a traffic light or to pass a car?

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**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:** [July 15, 2007, 10:48pm UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765/4 "2007-07-15T22:48:51Z")

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```
I read you reply so you do have separate controls. My money is still on the vacuum issue, but just not as strongly.
```

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [July 16, 2007, 12:34am UTC](https://community.cartalk.com/t/2004-suburban-air-cond-on-driver-side-goes-to-heat-while-driving/1765/5 "2007-07-16T00:34:11Z")

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Good Lord Star; give this nonsense a break.

Listen to Mr. Meehan instead.