2002 Pontiac Grand Prix AC Problem


#1

I have a 2002 Grand Prix. The AC is giving me a problem. It has two sliding switches on the dashboard panel that control the temperature for both the passenger and driver sides. The AC started to go in and out from heat to AC about a year ago and if you tugged on the sliding knobs outward a bit it would switch back to AC. That stopped working and you had to hold the sliding knobs out the whole time in order for the AC to work so I folded a little piece of paper to shove under the sliding knob to hold it outward and it worked for a while. Now it only puts out heat no matter what. My question is, are my knobs broken or is it something else? Expensive to fix?


#2

If this were my car, I would be calling for prices on replacement “switches” unless I planned on bypassing them somehow. I might pull them out before ordering on the outside chance that they might be fixed.

If these things are just variable resistors, they are no longer making contact between the pile and the brush (ie. worn out). I need to warn you that I have no real knowledge about how these really work. The behavior indicates that replacement will fix it.


#3

Remove the entire thermostat assembly and examine the controls. They’re likely just variable resistors, which are very cheap from an electronics parts store.
If you’re lucky, it might even be just a bad connection.