Pontiac: Heater/AC blower not working, three knobs, pontiac grand prix

Question
Tom- I have a 1999 Pontiac Grand Prix SE 4 door, 3.1 liter V6 automatic with air. The blower quit working and I need help. The panel configuration has three knobs directly under the radio.The left knob is the blower speed on an Off,1,2,3,4,5 scale, the middle knob is the temp selector, and the right knob is the directional selector i.e. defrost, floor, vent, etc. There is a push button between the middle and right knob to turn the AC on and off. At first the 4 lower speeds on the blower quit working, but the high speed(setting 5) continued to operate. Then the high speed would run sometimes and not at others. Now the high speed quit altogether, and it never works. The thing that was strange is that during the time that the blower was working on high when it wanted to, I noticed that when it would not work, neither would either right side automatic window. Now that the blower doesn't work at all, I notice something else. Originally, if you were to set the selector knob on "Maximum Cool", and turn on the fan, the AC would automatically run on high. With that knob in any other position, you would have to turn the AC on with the push button to get it to run. Now, when you set all the knobs to give you heat and turn the fan on to any setting, the AC clutch engages. The push button control for the AC does not seem to control it any longer-the blower speed knob does. I can hear the clutch because there is no blower running. Also, even though the blower doesn't work, the right front passenger window started to work again. The right rear window, however, still will not work. Where should I start. Any help would be greatly appreciated. Thanks, Mike

Answer
What mechanical work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made.

I would start by inspecting all of the wiring connectors near the blower motor for burnt electrical contacts in the connectors. Next I would proceed to the engine compartment and look for the same things. next would be to inspect all of the fusible links that are usually loacted where the battery cable attaches to the starter.

Think BACK and try and remember if ANY work entailed disconnecting ANY electrical harness connectors as this is usually the fault area.



Thomas