If your heat and air conditioning blower speed control stops working on the lower speeds (1-3), and only works on setting 4, you likely have a bad blower motor resistor. Replacement part cost $35.00-$46.00.



Be sure the blower fuse is good, see the 'glove box manual' that came with the car, if the fuse is good, then you need to replace the resistor, especially if the blower works on high (4) speed. The resistor allows the blower/fan to work on the slower speeds. High speed uses full power (no resistance) and still works because it does not need the resistor, replace the resistor to get the lower speeds.

The resistor is easy to reach, but hard to see, you've got to put your head way in under the dash. Under the glove box up against the firewall, on the bottom of the blower assembly, you'll see a wiring harness connector, with 2 phillips head screws on either side of the connector.

Here's a blower assembly schematic I found on line. Part #9 is the resistor you need to replace.



Pull the wiring harness connector off the bottom of the blower assembly. Use a stubby (short) screw driver, take out both screws and the resistor will drop down out of the blower assembly. Install the new resistor, reconnect the wiring harness and you are done. It's an easy repair, except for the standing on your head part.

I could not find any online information for this repair when I researched, it took me a while to put the pieces together, hopefully this article will give you a jump start.