[TylerFrankel]

Hey all! I’m new here, and newly the owner of a 1994 S10 2.2L with the 5 speed std trans. I picked her up for a great price, runs and drives, at 234k miles. It needs maintenance (tires and brakes) and the only other ‘serious’ issue is the air conditioning doesn’t work. However I’m hoping I’ll get lucky here; the dial that should click between different settings (ac/defrost/vents) seems to be broken... it doesn’t ‘click’ but rather spins around and around and the unit only blows defrost. I’m not familiar with how the controls work, but I’m hoping that if the dial can be replaced or repaired that I will once again be able to select different settings, one of which would be A/C. Is that how that works? Or, would I be getting cold air as-is with the defrost on and the temperature selector set to cold, if the ac system was working? Do y’all know, and if so, how hard is it to repair that? Thanks so much!

 

[Rhotpursuit]

Moved to Heating/Airconditioning.

 

[oldeerslayer]

It's impossible over the internet to diagnose your HVAC system, but if your switch is bad you'll need it to work whether it is the cause of the A/C not working or not. So go ahead and replace it.
I doubt the position selector is the cause since it's a vacuum switch. Defrost is the systems default position so you can see where you're going.
Probably a junkyard only part because of it's age. Just get the whole panel.
Have you looked under the hood when you set it to cold to see if the A/C compressor clutch is cycling on and off. Is one of the hoses from the compressor getting real cold? Should be.
It could also be the blend door actuator behind the glove box. Those go out often. Just 3 little screws hold it in, but the rear one is a real PITA to get out and back in.
When you set it to hot do you get real hot air and room temp air when it's set to cold? If so, then the problem is likely under the hood. Low on freon, a leak, or a bad compressor.
Hope this helps some.

 

[TylerFrankel]

It's impossible over the internet to diagnose your HVAC system, but if your switch is bad you'll need it to work whether it is the cause of the A/C not working or not. So go ahead and replace it.
I doubt the position selector is the cause since it's a vacuum switch. Defrost is the systems default position so you can see where you're going.
Probably a junkyard only part because of it's age. Just get the whole panel.
Have you looked under the hood when you set it to cold to see if the A/C compressor clutch is cycling on and off. Is one of the hoses from the compressor getting real cold? Should be.
It could also be the blend door actuator behind the glove box. Those go out often. Just 3 little screws hold it in, but the rear one is a real PITA to get out and back in.
When you set it to hot do you get real hot air and room temp air when it's set to cold? If so, then the problem is likely under the hood. Low on freon, a leak, or a bad compressor.
Hope this helps some.

Thanks for all the pointers. I don't know/understand fully how the AC settings work on this yet... but if it blows cold air no matter what when set to the 'blue' range on the temp control and has air blowing, then something additional is wrong on top of the existing issues because I don't get cold air. In my other car, I can set the temperature knob to cold and turn the blowers all the way on, but no cold air comes out until I press a dedicated "A/C" button. I guess that's not how this works... is it then, impossible to get straight outside air through the blowers when the AC system functions correctly, since it will always blow heat or air?

 

[Rhotpursuit]

Have you acquired a new control panel for it? I'd go j/y diving rather than the parts store. There's another ac thread with control panel issues...they were Dorman junk.