It's 30 degs here with heavy snow and while driving with the heater on I noticed my heater isn't putting out the heat like it should on both front and rear heat. Looking under the hood I noticed my A/C compressor clutch engaged and the compressor running. I'm thinking this isn't supposed to be running when the heaters on. It shuts off when I turn the heater off. Does anyone know if this is normal ? If it's not normal does anyone know what would cause it to running with the heater on ?

 

The compressor runs except when the selector is on floor only or vent only. Any other of the positions turn it on to remove moisture from the air. This is to aid in keeping the windows from fogging up.

 

.. and this is all in your owner's manual.

Steve