Hvac control doesn't.....

[02ragtop t/a]

My HVAC control recently started "spinning" on the shaft w/out setting any functions...eg: max air, air, defrost, etc. Is it the knob itself that went bad or do I have to pull apart the whole center dash to replace the shaft in the HVAC control? Anybody else ever have this problem? It DOES work the controls but I have to turn the control VEEEEERRRRRYYYYY slowly and feel for the detents at each function. It sometimes is pointing to the floor when it is off. Not Good.

[SMWS6TA]

1st pull the knob off and look on the back side. It should have a flat space kinda like half a circle that the shaft sits on. If this has been rounded out completely then all you should need is a new knob.

Knobs - junk yards or parts cars


Next if the knob is still good - try turning the shaft without the knob on. Should be able to turn it by hand but needle nose pliers work also, just don't use a gorilla grip. It should rotate freely form one setting to the other. If it doesn't a new one is needed.

Dash Unit Controller @ gmpartsdirect = $122.65

[02ragtop t/a]

I have a feeling that the knob itself is the culprit, the shaft spins ok if I turn the knob real slow. Haven't had a chance to check it, will get to it tomorrow. Thanx

[02ragtop t/a]

Yes, it was the cheap-ass plastic, made in China, knob. New one: $21.19 from Frank's GMC/ Truck. Problem solved. Thanx for your responses.