HVAC controller issue
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Joined: Mar 2018
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HVAC controller issue
2003 Suburban. Having HVAC controller issue. The fan speed control works ok. the temp selector does not change air temp. only blowing cool air. unable to change air flow from floor to dash to defrost vents. only blows from dash vent. Also the back lights do not light up when headlights are on.
The rear controller seems to work ok. I can change from cool to heat and change the fan speeds. but those are on a different control panel. The HVAC fuse is ok in the box under the hood. I ran out of time this past weekend to check any other fuses. Also unsure if the A/C compressor comes on when I turn on the A/C but I think that maybe a different issue.
thank you for any help.
The rear controller seems to work ok. I can change from cool to heat and change the fan speeds. but those are on a different control panel. The HVAC fuse is ok in the box under the hood. I ran out of time this past weekend to check any other fuses. Also unsure if the A/C compressor comes on when I turn on the A/C but I think that maybe a different issue.
thank you for any help.
Last edited by Tyger255; Mar 8, 2018 at 8:31 PM.
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CF Beginner
Joined: Mar 2018
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So today before going to work I checked all the HVAC fuses I could find in both fuse boxes and everything checked good. Pulled the HVAC controller out of the dash again and make sure both plugs were in good, they are. None of the pins are bent, the plugs look ok as far as I can tell. Still wont change from cool air to warm, only blowing cool. only blowing from dash vents, cant change to top defrost or to floor vents. Going to get a Haynes book on my way home in the morning to get some wiring diagrams but I'm not sure what to check from here.
Administrator
Joined: Apr 2008
Posts: 7,573
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From: Austin, Texas
I can't recall if the HVAC relearn procedure applies to the 03, you can try it, pull the 10amp HVAC fuse for 10 seconds, plug it back in, put the key in start no crank and wait about 1 min to let the relearn procedure take place, do not make any adjustments to the controls while in relearn.
After one minute is done, start the vehicle and see if things work, if not I suspect your blend door actuator(s) are the problem , you may hear them moving during the relearn.
After one minute is done, start the vehicle and see if things work, if not I suspect your blend door actuator(s) are the problem , you may hear them moving during the relearn.
CF Senior Member
Joined: Oct 2006
Posts: 464
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From: Massachusetts
I had a similar problem with my 2002 Tahoe. For mine it, I needed a HVAC controller with new programming and a re-routing of the wires leading to it. I don't know if this could pertain to your 2003 suburban. I have the service bulletins they used on my Tahoe in the thread I have a link to below
https://chevroletforum.com/forum/tah...e-floor-88747/
https://chevroletforum.com/forum/tah...e-floor-88747/