Jason M: I need help with my 05 Trailblazer a/c. It started blowing hot air on the passenger side and the rear while blowing cold on the driver side. When I turn the vent on it just blows defrost and on the floor.
Sparky: It sounds like the battery may have been recently disconnected and the system did not properly recalibrate. I would start by performing a recalibration. Remove the HVAC B fuse in the rear fuse box for one minute. Reinstall the fuse and then start the engine. DO Not touch anything and allow the engine to run for at least one full minute. Turn the ignition off for at least ten seconds but no more than thirty seconds. Restart the engine and check the system performance. If you still have a problem it is likely that you have faulty actuators. The mode actuator in particular is very common to fail.