Operation CHARM: Car repair manuals for everyone.

Front Defrost

The front defrost mode is the only setting that is not controlled by the automatic HVAC system. When defrost is selected, by the vehicle operator, the A/C compressor is activated. The blower motor will be activated, regardless of coolant temperature and air will be directed toward the windshield. The rear window defogger does not affect the HVAC system at all.