Drivers Side Blowing Hot Air

[08SierraZ71]

hey guys battery went dead in my truck own fault left radio now after boosting it drivers side blowing hot air all the time passenger side works fine, whats the fix? 2008 gmc sierra thanks

[mhorgan]

My guess is that your HVAC control module might have shorted out, or one of your cabin air temperature sensors went bad. Usually when one or the other goes bad in those dual zone systems, it will default and blow all hot or all cold. I have a bad sensor right now with the rear air im my 03 Tahoe, but it blows all cold. That might be one you have to diag at the dealer. They might be able to reprogram the HVAC module but if it shorted you'll have to get a new head unit, then have it reprogrammed. If one of the sensors is bad, they're all in the headliner. Good luck.

[08SierraZ71]

hey thanks for the information, fixed the problem disconnected positive terminal than reinstalled all seems ok

[rscharfe]

2009 Silverado LTZ 4x4

My battery was dead and after jumping, my climate control would only blow hot air, from both sides.

Here is the fix if you have LTZ with power seats.

Turn AC off, then turn ignition key to "on" position. Press and hold the #1 seat memory button until it beeps. Then start the motor and turn the ac on. You should now have cool air. If this fails, try it again. I have had several dead batteries and sometimes the passenger side blows hot and sometimes both sides are blowing hot. This information is not in the owners manual, but should be.

It does tell you to turn everything off prior to jumping a dead battery. This will sometimes prevent the AC malfunction but not always.