Does a compressor still run when the heat is on in your car?

not necessarily, the AC compressor pulley is always spinning because is run by the engine belt, but it will not work unless you press the AC switch on your AC control, the heater on your car works with engine coolant, so if your car has been on for 2 minutes your coolant is not hot yet but after 10 minutes that your car has been running the coolant will be hot and thats how you feel the warm air inside, hope this helps....

Depends on the make & model - - - - on all of our recent cars, the compressor runs in all modes to dehumidify the air........but there are manual override switches to turn it off if desired. On some 100% automatic systems the compressor runs in all but the coldest temps.

Your A/C compressor will only be engaged with either the A/C is on or the defrost function. It will not engage with the heater on, or the fan.

It still comes on when you have your car heater set to defrost.