I have been trying to fix the heater fan in my truck. I have checked the fuse, and replaced the motor~ still no air movement.
Any ideas?

. Check the blower motor relay in the under hood fuse/relay box.

. Check all under hood and under dash fuses with a test light or multimeter.

. Check if the fan motor will run on High. If it does, the problem may be with the blower motor resistor.

. Check continuity in the blower motor switch.