Air conditioner not working

Hello Ken, do you have the complete circuit of the A/C system? I have a same problem.

Thank you a lot. I beginner here.

This season when I turned my A/C on for the first time I realized the air wasn't getting cold. I put a set of gauges on it and it was barely low so I topped it off with no change. Like many of the Avengers around this year I have a variable displacement compressor and I can tell from the gauges as the low side drops and high side rises that it is working, although not as strong as it should be. I noticed that the fan wasn't spinning and while checking around I unplugged the A/C pressure switch which looked good and when I plugged it back in the fans started up but only spinning at a slower rate than they should be. The blend doors function correctly through all the settings and heater gets good and hot when I switch over to it through all appropriate vents. A mechanic friend of mine hooked up a high quality code reader which showed no faults or problems. It confirms that the fan and compressor are both working and receiving signal. It also shows accurate readings on the ambient and evaporator temp sensors. The voltage return through the pressure switch should be about 5v and the code reader shows it's just getting back 1.25v so I swapped out the pressure switch with a new one and it's still happening. I've confirmed that both the old and new pressure switches are good. It seems like the compressor and fans are being moderated down or are not receiving the proper signal to spin up. I'm out of resources and need a mechanic who has seen something like this before please.

When I mash the accelerator the pressure equalize at about 80-90 psi. After a minute or two of idle the low side drops to around 45psi and gets cold to the touch. The high side climbs to 125psi and gets extremely hot of course. The equalization makes me wonder if the computer is trying to moderate the increase in belt speed by reducing voltage to the compressor which makes the swash plate go to 0 degrees, or basically no compression until I let off the gas pedal. But even when the compression drops the low side I'm still just getting ambient air temperature out of the vents essentially.

I completely agree about where the pressures should be. However I can't help but think that the fans spinning slowly and only coming on when I unplug and plug the trinary switch is connected to the same root problem. If the fans are being moderated down to a slower speed then it would possibly make sense that the compressor swash plate is being moderated to less that it's full 40 degrees and not delivering full compression. Which could explain the pressures I'm seeing. If the exp valve is smoked and I fix it there is still an electrical issue going on with getting the fans to spin at full speed like they should be. If I jump the pins on the plug going to the trinary switch the fans spin like a hurricane so I know they have it in them.

And let me say thank you very much for helping me work this issue.

That makes sense! Thank you very much. I'll give it a shot.

One last question. I'm finding online that my model does not use an expansion valve but does have an orifice tube. Are you able to confirm this?

Update: Problem fixed. Orifice tube good but compressor solenoid control valve in the underside of the variable displacement compressor was out. On research these control valves have a high fail rate even though the actual compressor does not. Valve was only allowing the compressor to run at idle without having full angle of the swash plate and full compression. This accounts for the low and high side moving in the gauges but not as much as they should have been.

Hope this helps the next guy.

Low side 30.
High side about 180.

I have the vehicle listed above 2.0L engine 420a, it came from factory with the Mitsubishi engine that was also present in the 1995-1999 eclipse GS 2.0L.
My A/C compressor clutch from when start the car only work/is engaged and cooling for about 1 minute after that it shuts off and never engages again unless you stop the car, let it sit for about 2 hours and start it again.
I did the bypass at low pressure send it with the paper clip and the A/C compressor clutch engages but for only about 1 minute.
I replaced pretty much every part in the A/C system I know and was able to search about, I put only new OEM parts, that includes:

A/C Denso brand new compressor.
Low pressure sensor switch that sits in top of drier.
Receiver drier.
Expansion valve.
A/C Evaporator unit.
Switch at evaporator/blower motor resistor.
A/C Condenser unit.
A/C module switch.
A/C switch dash/push button (cold).
A/C switch at Ac control panel inside.
Heater fan.
Recharged with Freon, Freon system pressure tested okay with no leaks.
Checked all the fuses at engine fuse box, replaced with other ones.

Do you have an idea of what the problem would be? To me it seems that when the pressure builds up in the system the A/C compressor clutch shuts off and stays off unless I stop the car, let it cool for some hours. While the clutch is engaged and running, the A/C is blowing cold air inside car as it should.