Question about 2004 Chevrolet TrailBlazer

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Changed battery and now the dash vents don't work

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One of two things has happened, one or more of the HVAC actuators has failed or the HVAC recalibration of the actuators when the battery was connected failed. To recalibrate the HVAC actuators do the following;
You can pull the battery off again for a few minutes, or easier: pull HVAC B fuse #36 in the rear fuse block (under the rear seat - driver's side) for 2 minutes. Then put it back in with the ignition off. Then turn the key to the RUN position, but don't start the engine. Don't touch the HVAC controls for 2 minutes, and you should hear the actuators and blower motor going through all the modes and speeds.
If this does not solve the problem, then the HVAC system will need to be troubleshot.

Posted on Sep 11, 2010

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