Chasing dash A/C gremlins

[Empty_Nest__Soo]

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.

I noticed that pushing the A/C button, most times does not light up the little light (the light which indicates that you have engaged the A/C compressor).

If the “A/C” light is on, I’ve noticed that turning the rotary selector from “Off” to “Recirculate” doesn’t work, but if I turn it from “Off” to “A/C” it works, and if I turn it from there back to “Recirculate” it seems to select that mode and work fine.

I’m thinking it has something to do with a control for the A/C. The controls appear to be electrical. Is this something I have a chance of troubleshooting myself? If the controls are some sort of little black box, I have no qualms about replacing it myself, so long as I can identify it. It occurs to me that the problem with the little push-button switch may be something mechanical or resulting from corrosion/dirty contacts. It could be that a little shot of silicone spray will help. (It used to keep the switches on my motorcycle, often exposed to the weather, working well.)

Thoughts?

Wayne

[Empty_Nest__Soo]

MountainAir05 wrote:
I would use CRC or others contact cleaner, not silicone spray which most have a residue.

OP here.

Good point about the residue, which probably adds a protective barrier for switches on motorcycle handlebars exposed to the elements.

I applied some CRC 2-26 around the perimeter of the A/C button without taking the HVAC control panel out of the dash. That seemed to help. The A/C button doesn't always stay depressed, and the light on, but it is much improved.

I'm not sure how to get the control panel out of the dashboard without removing a number of other things that are in the way. I may wait and see on the rest of it, since it appears that I can now get the A/C turned on, even thought the controls are not working perfectly. We'll see what improvement we see next trip.

Thanks for the replies!

Wayne

[rockhillmanor]

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.

[MountainAir05]

I would use CRC or others contact cleaner, not silicone spray which most have a residue.

[1BryNelson]

Pull the control panel/box out and clean it, could really be a simple problem of dirty contacts or in your part of country corrison from humidity. We don't suffer from that problem in AZ very much.