Anyone have their AC switch go bad

With the selector set to the upper vents of both upper and lower, my AC is intermittent. Sometimes it works and sometimes it doesn't. However, all I have to do to get the compressor to kick in and work is turn the switch to defrost. Then the AC kicks in.

Are there some things to try, or just get a new control unit from a junkyrard?

Not sure if it is electrical, My 2004 has 3 air positions where the A/C does not engage compressor.

The coldest position (re-circulation) turned to left seems to be coldest setting.
If it is low on refrigerant, it may not cycle when you want it to engage.

I think it's just brass sliding contacts on the knob and a track on the circuit board, might just need a clean or a tweak on the contacts to increase the pressure on the board.

Well ... crap. Yesterday while switching to defrost to get it to kick in, one time I got a loud thump while engaging on the freeway. Check engine light came on (random misfire). Turned off air and drove home. Safely at home I went to defrost to kick in in again, got a thud as the clutch engaged, and it burped out a cloud of refrigerant from the side of the compressor.

It then worked a little better for a while, but now only kicks in again if I go to defrost.

So I may have 2 problems or 1 -- could be that my controls are not working well, and/or it could just be my compressor is failing.

Its a Santech kit I put in 6 years ago from Autozone. Maybe 6 years is the life of a Santech compressor.

Definitely, the serpentine belt bounces more on the idler pully when the AC clutch is engaged via turning on the defrost. Suggests some bindings or resistance in the compressor when engaged.

Need a new compressor for sure. So, supposedly I have a lifetime limited warranty from Autozone -- but the same kit is over 200% higher in cost from them now (over $500 when I paid just over $200 in August of 2017).

May look elsewhere.

Anyone else have to re-do AC after 6 years?

My check engine light cleared today confirming for me it was caused by the compressor causing the serpentine belt to bind

Well In my former liberty 2007, I had to replace the AC after 7 years.

jeepop said:

Well ... crap. Yesterday while switching to defrost to get it to kick in, one time I got a loud thump while engaging on the freeway. Check engine light came on (random misfire). Turned off air and drove home. Safely at home I went to defrost to kick in in again, got a thud as the clutch engaged, and it burped out a cloud of refrigerant from the side of the compressor.

It then worked a little better for a while, but now only kicks in again if I go to defrost.

So I may have 2 problems or 1 -- could be that my controls are not working well, and/or it could just be my compressor is failing.

Its a Santech kit I put in 6 years ago from Autozone. Maybe 6 years is the life of a Santech compressor.

Definitely, the serpentine belt bounces more on the idler pully when the AC clutch is engaged via turning on the defrost. Suggests some bindings or resistance in the compressor when engaged.

Need a new compressor for sure. So, supposedly I have a lifetime limited warranty from Autozone -- but the same kit is over 200% higher in cost from them now (over $500 when I paid just over $200 in August of 2017).

May look elsewhere.

Anyone else have to re-do AC after 6 years?

Click to expand...

What does is cost to ask Autozone about replacing it? That would be my first option. Personally not a fan of either Autozone or O’Reilly as to quality. Put an “O” battery in the Liberty two years ago. It has failed every winter since. They replaced it no charge last spring. Headed there today with another battery shaped boat anchor.

I’ve already called my good supplier about a Deka replacement. $170.

To revisit a year later .....

Finger crossed I fixed the AC. For a year I have had intermittent AC when I have it on re-circle or the upper vents, but 100% ac compressor kicking in when on defrost. No more check engine lights when the compressor kicks in, so that mush have been just because of my kicking it in and out so many times in rapid succession. With it being hot again I started testing again, and just keep thinking its the AC heat control module in the dash.

I noticed my local Autozone sells a Dorman refurbished unit. I mean everything Dorman sells for this car the original part eventually has to be replaced. That seem to be their business model -- make the parts for Jeeps that ware out over time. Given how many parts eventually wear out on these things, it is a solid plan -- my Jeep is 25% Dorman

So I took out the AC controller unit. The tabs are tricky, but I eventually got it open without breaking any of them. I cleaned all contacts. The AC button is on the circuit board and not removable, but I could get the red straw on my contact cleaner to where I was able to send some cleaner under it.

Put it all back together and so far, I have AC on demand again. So I do believe it was oxidized and dirty contacts on the AC heat control unit.