Have a problem with the interior air vent system. Have a 99 DX with the two turn ***** on the right side of the console.
The fan speed **** is like a volume **** on a stereo. What happens is that the fan comes on intermitently....if I turn it to the middle, sometimes air blows at medium speed and sometimes not....sometimes you can hear it blowing and then it slows down and then goes back up again. It does blow at high speed when **** is turned to high...this is the only constant.
Does this **** work like a rheostat or am I looking at some kind of computer module or chip?

......any ideas on how to fix this?......thanks!

 

could either be the switch assembly in that controls the speed of the fan or the fan motor is going. happened in my parents car and it was the fan motor dying.