I have a 99 Sport 4x4 that has a couple weird problems. One of them is that the AC appears to be on even when it should not be. For example, the position three clicks clockwise from max air still has ac air coming from the dash. I attempted to fix it by replacing the heater switch console but the problem still exists. I have had it to the dealer 3 times last summer and they are more than happy to keep throwing money at it. Any ideas?

 

Is your problem that there is cold air coming out of the vents (A/C compressor is on) or that air is coming from the dash vents when the dial is set for floor or defrost? If the A/C compressor is running, many cars cycle the compressor when the directional dial is set to defrost and the outside temp is above about 40 to lower the humidity and keep the windows free from fog. If you can't get the air to stop coming out of the dash vents, make sure you visually set the dial to floor only. I noticed that the dial on my 02 has intermediate click positions and it is like 5 or 6 clicks from the two max A/C positions to floor only. If you have the dial set correctly to floor only and air is still coming from the dash, it sounds like it may be a blend door problem (assuming Dodge has that setup.) The actuator on the blend door can fail or the door can get hung up and the air doesn't get redirected.

 

and to follow on that note, also visibly check if the compressor clutch is running. If the little yellow light oon the dash is off, the clutch should be too.

 

To clarify the problem a little: Cold AC air is coming out of the vents when the indicator is set on a position other than the 2 AC options. I drive a 99, I have no yellow light.

 

ok, wasn't sure what year the compressor switch and light was used on the dash rather than the clockring. I'd still check if the compressor clutch is staying locked up when it shouldn't.

 

The dealer replaced the AC clutch last summer which supposedly fixed the problem. I tried replacing the switch unit. The only thing left is the actual controls computer isn't it? Where is that even found and how year/option specific is it?