For the past few weeks my AC fan switch has been not been working on the 3/4 ON position ( the place I keep it most) but works fine in the other 3 positions, has anyone been able to take it apart and fix or replace just the switch or is all that and the HVAC controls sealed and has to be replaced as a unit?

 

I think someone said that there are resistors in the switch assembly which set the speeds. I would imagine that if you could get it apart without destroying it and the resistor for 3/4 is not discolored, then you could go to radio shack and get a replacement. Just be sure to get one of equal or greater of a wattage rating.

 

Just from looking at the back of the controls on my car and others, it doesn't look like it's user serviceable. Probably have to find another one in the junkyard. You could swap your button and two slider covers (as well as the faceplate) if you can't find one that looks exactly the same.

 

The switch is replaceable as is the vac control unit.

I once had a fan speed problem, but I don't recall what speed/speeds. In my case, the resistor had burned in two (under the hood--five minute fix, should that be the problem).

JamesC