Random A/C compressor INOP?

[azaizai]

So, as is typical with increased temperatures, my A/C has randomly been blowing hot. Not like hotter than ambient temps hot but definitely nothing going on in the A/C department. Typically if I drive and suffer through it though it'll randomly start working again and perform excellently. I hadnt really thought too much about it until the wife started to complain...and then I had to get the wrenches turning on my own rig for once.

So today after work I hooked up the machine and decided to check the numbers. With the AC full blast, recirc, open windows and temp gauge in the center vent I was getting something like this:

Ambient: 75-77 with near 100% humidity (it was raining, garage doors were open)
Discharge temp: 60 with no real fluctuation
Low Pressure: Around 38 but when the fans kicked on it would drop 10 psi or so.
High Pressure: 225 I think, same thing though...fans kicked on and pressure would drop.

The low pressure hose felt relatively cool to the touch, nothing dramatic. The high side hose was definitely hot, not scalding but I wouldnt have wanted to leave it there for too long.

Running out of time (and uninterested in more diag) I decided to recover the refrigerant and start over fresh. It only recovered about 1.50 lb or so. The other odd part was that about 2-3 minutes left on the recovery it was in a vacuum on the gauges and then suddenly there was 20-25 psi on both dials. I've never really seen that before (and no experienced techs to bounce ideas off of). Oh...it also didnt remove any oil.

So I recharge with 1.91 lb (All-data said 1.80 +.10-.20) and left the oil alone. Get that all done and no AC to speak of...clutch is not engaging at all. I check fuses, try knocking on the compressor and any protruding things (hoping for a valve to get randomly unstuck) and look for loose wiring. No luck. I check all-data's diag chart and get discouraged (and remember i'm out of time). I also notice that I can put a hand on the condenser up front and its not even remotely hot (just 'cause the fans are running and the compressor wasnt pumping?) Assuming the worst, I just button everything up and head home.

About 10 minutes down the road, A/C is working perfectly. I got the wife's temp probe from the kitchen...50 degrees discharge with the windows down.

Sooo...TL/DR wtf is going on? My ideas so far are: randomly malfunctioning ambient air temp sensor (thought it was cold, didnt activate AC clutch), randomly clogging condensor (it was practically cold to the touch when the AC wasnt working). Thanks in advance, I know it was a long read....

[ShipFixer]

Not saying this is absolutely your problem, but when this happened to me it was a partially clogged/failing radiator rather than the A/C system itself. My A/C would randomly go warm during drives. It turned out to be the engine getting slightly too warm and shutting A/C off to cool down. It wasn't hot enough to show me overheating on the dial or the dummy light (mine work, I've seen it!) but it was just warm enough to cause other things to happen.

Took a Nissan dealership about a week to diagnose, they had to let the truck sit idling in their bay for hours to chase down what it might be...

[azaizai]

Hmmm that's a good one. Would definitely make sense as to why the compressor would totally stop working at times and others work just fine.

Now to recreate it lol

Thanks!