heater setting low/med/hi prob

Hey all ive got a prob with my heater blower motor: I just recently got the car and dont know all the little tips and tricks lol.There are 5 hearter settings:off-low-Med-Med/Hi and HI, when i 1st got the car about a month ago Off-low-Med/Hi and Hi all worked (Med) did not. Now all that works is OFF and HI ,I changed the control switch and the new one does exactly the same thing. a couple of Gm owners told me they had the same prob but it wasnt the switch it was a curciut board under the dash.Just wondering if anyone has had a similar prob and how they fixed it ,Any and all comments welcome TY ........Jeff

You don't mention if this care has Automatic Climate Control (ATC) or not. I am not sure about the ATC models, but the non-ATC models have a built in diagnostic center that will aid in determining the problem. Details are listed in the Haynes manuals. My guess is that the mixer control is defective. If you need help accessing this feature, let me know and I will scan and post the procedure.

Its your Blower Fan Resistor. Located on passenger side under dash.

Its your Blower Fan Resistor. Located on passenger side under dash.

Refer to this. http://www.automotiveforums.com/vbulletin/showthread.php?t=927899

Midrange is correct .Blower motor resister is bad ,you will have to cut a piece of the blower motor housing for the new part to fit,as,it is redesigned. Easy job.Good luck.