Taurus-2002 Blower motor only runs on high

[Hevehank]

The blower motor only runs on high. How do I determine if its the relay, switch? Where is the cheapest online store to order ford parts from?

[KimMG]

Switch: Test the different settings for continuity.
A wiring diagram will show the schematic for the switch.

[shorod]

Originally Posted by Hevehank

The blower motor only runs on high. How do I determine if its the relay, switch? Where is the cheapest online store to order ford parts from?

Does your car have the electronic automatic temperature control? If so, you probably have a bad blower motor controller. High speed is controlled through a relay, lower speeds in this system are controlled via a transistor and PWM circuitry.

If you have manual heat and A/C controls, then high speed is straight through and lower speeds are determined by lowering the motor current through resistors. If the common terminal to the resistors is open, it could cause what you are experiencing.

The resistors or controller should be mounted in the blower motor housing and you can check at the connector for power in the various settings if you have the resistor setup. If you let me know which type of HVAC controls you have, I can possibly provide more detail.

-Rod