Chasing dash A/C gremlins

Empty Nest, Soon wrote:
Our 1997 Sahara has issues with the dash air conditioning. I’m pretty sure the problem resides in the controls.

Late last summer, it acted up a time or two. It might cool, or not. Switching the rotary selector dial to “Off” and back to “A/C” would get it going again. When the weather got cold, the heat worked just fine.

Now that warm weather is here again, I’d like to get this sorted out. When the A/C runs, it is cooling fine. The trick seems to be to get the controls to tell it what to do........Is this something I have a chance of troubleshooting myself? ......Thoughts?Wayne

Mine did the exact same thing.
I thought no problem go to the dealership and get a new control knob put in. WRONG.

Unlike years ago when all you had to do was replace the control knob, now it's all connected as an assembly deep down at the bowels of the dash to a vacuum pump or whatever.

They said it would cost me $600+ bucks because the part was an assembly and the labor to dig down to the bottom of the dash to replace it and leaving the MH over night and the next day.

It was stuck on a/c and I was heading to Florida so I left it and I don't touch it anymore. Don't need no stinkin heat anymore anyway.