Rear heater blows cold air?

Tiny
KILLA1982
  • MEMBER
  • 2003 GMC YUKON
  • V8
  • 2WD
  • AUTOMATIC
  • 90,000 MILES
My rear control heater is only blowing cold. Even when using either aux or front controls. Either way. Its only cold. Have anyone ever had this problem and if so. Can someone give me some ideas on what might be the problem? I really appreciate it. Thanks.
Wednesday, December 26th, 2007 AT 12:29 AM

1 Reply

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
This is because the blend door on the auxiliary unit has failed. I attached the guide here on how to replace a blend door.

https://youtu.be/tY6M92fA2ug

However, your specific instruction is below because this is the aux unit and that is slightly different.

Let us know if you have questions. Thanks
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Monday, January 18th, 2021 AT 3:18 PM

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