Having problems with your 1985 Oldsmobile Cutlass Supreme ?
1985 Olds Cutlass Air Blowing out Defroster vent
Anybody can just change parts until the problem goes away. Answer this first: Was the underhood of the car recently serviced? and did this problem appear at that time? Perhaps there is a vacuum line broken or disconnected. The Heat/AC idepends on vacuum to actuate the servos that direct air passage. I know that the control cluster is known to fall apart, but check vacuum lines first.
The most common problem that causes this is a bad temp control, the actual selector module in the dash of the car. Try replacing this.
Repair Help & Product Troubleshooting for 1985 Oldsmobile Cutlass Supreme
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