I will do my best to describe the problem I am having...if more info is needed let me know. I have a 96 4runner with an A/C issue. The problem is that is works when it wants too. Here is list of things that have been done.

New compressor & clutch
New hoses
Pressure checked and no leaks. Pressure where it needs to be.
New thermastat installed. Never overheated but put one in anyways. Runs @ normal temp.
Fan blows good
Light on A/C switch comes on

When I say it works when it wants too...I mean just that. First thing in the morning won't work...later that afternoon get in it and works good. Sometimes it will work just fine and then start blowing hot. You just never know when it will work or not...hot...cold doesn't matter. Very erratic.

Any thoughts on what I should check next?

 

I have a similar issue, My AC will not work when cabin pressure gets hot. Have been able to avoid failure by parking in shade, but that is a ridiculous solution. Stuff I have read suggests low pressure switch and expansion valve replacement. But these all seem to be fishing expeditions. I will post if I find a resolution for my issue as to possibly help ya.

 

Thanks Sky...leaning towards expansion valve as the clutch is engaged and still no cold air. I believe the clutch on the compressor will not engage if the low pressure switch is not working correctly. Not sure...just a guess. Please let me know what you find out. Thanks again.

 

Replaced the expansion valve and problem is solved.

 

I may have to give that a try. Good to hear you got it fixed. Thanks for the followup. One question, did you have to evac the system?

 

I had a shop do it...they have a machine to capture the freon and reuse it. Cost me 290 parts and labor.