Fan blower knob only works on certain numbers

[OhMyAchingCar]

Something weird is happening with the fan blower knob in my 1997 Pontiac Grand Prix. Doesn't matter if I'm using heat or air. It only works on certain numbers but not on others. I took it to my repairman several months ago and you might know it was working on all of them for him so he was not able to do anything.

Right now, it will only work on '3' sometimes when it feels like it and the only number it works on all the time is '5'. Seems like it should either work on all numbers or none of them. Any clues I could give to my repairman that might help him to fix this before it drives me crazy?

[GTP Dad]

Welcome to AF!!

Have the repair man change the blower motor resistor which is located next to the fan motor under the dash. This is a common issue and is not expensive to repair. The part is about $45 and it will take about one hour or less to replace it.

[marz1129]

I have the same problem on my 1997 GTP. I have replaced the resistor, the fan motor, and the fan switch but it still only blows on setting number 5. Does anyone have any suggestions for this problem?

[OhMyAchingCar]

Thank you so much for your help, GTP Dad. I will tell him what you said and, hopefully, that will fix it. And, thanks for the welcome too. With the way things are going looks like I found this forum just in time. I love my Grand Prix but she's getting older and needs a band aid now and then.

[GTP Dad]

If the resistor doesn't fix it you will need to change the ignition switch. NOT the part where the key inserts but the ignition pigtail at the bottom of the steering column. They will wear out and cause a problem with the other circuits especially the fan circuit.