1998 Camry

I'm having a problem with the fan speed of the climate control. At first, only the low setting wouldn't work, then the two lowest settings stopped working. Now, I can only turn the fan on by having the switch set to high. I took apart the switch and cleaned the contacts which didn't help. I also tested the voltage into the blower motor. One leg goes 12v hot and the othergoesground at the setting that works. The other settings seem to maintain the 12v hot on the one side but the other side shows nothing. No voltage or ground. Any ideas? Might there be an interface between the fan speed control switch and the fan that went bad? Any help would be appreciated. Thanks.

 

Sounds like the variable resistor has burned out. Basically low and medium speeds are run through a resistor to drop voltage to the blower motor. High speed bypasses the resistor to provide full voltage to the fan motor. Ground should be constant in either setting. This doesn't quite coincide with your measurements- but this is basically how the system works.

J

 

how do you change the variable resistor?