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?

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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.