Rear heat not working

Tiny
NOSAGROY
  • MEMBER
  • 2001 CHEVROLET SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 105,000 MILES
My 2001 suburban rear heat blend door isn't working. I have tried replacing with a new rear air controller and also a new blend door actuator. The blend door does not seem to be stuck because I can manually rotate the door quite easily and then get hot air. However, when I turn the air/fan off the blend door goes back to the default position and then I get cold air again. What could be causing the problem?
Sunday, November 28th, 2010 AT 5:31 AM

7 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Is it vacuum actuated?
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Sunday, November 28th, 2010 AT 5:37 AM
Tiny
NOSAGROY
  • MEMBER
  • 4 POSTS
I don't think so. It looks to be all electric controls
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Sunday, November 28th, 2010 AT 5:55 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Okay, check to see if the blend actuator is getting power. (Sorry I had to ask. It seems like they change things every 5 minutes.)
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Sunday, November 28th, 2010 AT 7:16 AM
Tiny
NOSAGROY
  • MEMBER
  • 4 POSTS
I'm not the best at electrical systems, but I think it is getting power. I took the actuator off and when I adjusted the temperature the gears moved on the actuator. - I did some other research over the weekend and saw someone post that they had a similar problem and needd to have the computer reset. Does this sound possible? They said it had to be done at the dealership though. Is this true?
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Monday, November 29th, 2010 AT 7:44 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
That is possible, but if the actuator is moving, it sounds good. When attached to the blend door, does it move the door?
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Tuesday, November 30th, 2010 AT 12:14 AM
Tiny
NOSAGROY
  • MEMBER
  • 4 POSTS
No, the door doesn't move when the actuator is attached. I can turn it with my fingers though very easily.
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Tuesday, November 30th, 2010 AT 2:06 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Then the actuator must be bad and unable to move it.
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Tuesday, November 30th, 2010 AT 12:41 PM

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