All the details in this thread:
https://www.ford-trucks.com/forums/1...r-testing.html

 

Great info. Is there a link to more info about this adjustable switch?

Do you know by chance what the high side pressure switch is looking for? On mine the pressure relief valve has purged twice while parked making a mess before I could shut it off. From what I have read that valve is not supposed to vent until 480 psi high side, and I have watched mine creep all the way up to 450 last week playing around with the gauges and it held. Does this sound like a possibly faulty high side switch? ForScan PID for that switch is "ACP" and it shows "Open" (Okay) whether the system is on or off, so I can not see if it is responding and working like I can with the low side switch.

 

450 = overcharged, IMO.

 

Granted your AC system isn't contaminated/blockage there's a high chance you fan Clutch isn't working, just fixed this the other day in my work truck..

Here's what I posted on the other thread.

"Just my luck, my work truck started doing the same thing this past week, put it off for the entire week as I noticed it only happened when I was idling and increasing the rpm's to 2k took care of that blow off/ safety valve. So just recharged it and strated to diagnose the problem today.

Since my AC system was all replaced 5+ years ago, so I doubt it was blockage in the system, and evacuating and removing the Orifice tube confirmed that the system is still spotless.

Gauges were reading very high at idle in the shop with ambient temp in the high 70's, threw some water in the condenser and readings immediately went to the upper 30's on the low side in the 190'ish in pressure.

The fan was spinning "fine" but noticed that I couldn't feel air being sucked in, thought it was weird, since you can usually feel air being sucked in thru the condenser. So long story short the fan clutch was capoot. When I removed the fan clutch the temp coil was covered in oily dirty, and when spinning it by hand it felt like a "good" clutch, but the faster I tried to spin it the looser it got. So a new fan clutch from the local parts store and AC is up and running 100%.

So check the fan clutch just to make sure it's actually working right, ad make sure all the fins on the condenser, trans cooler, IC, and radiator are clean of debris"

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My money is on too much oil in there. Then when filled with 2.5 lbs of refrigerant the system is overfull. But I haven't taken anything apart yet.

 

I did replace the fan clutch back in 2017 or 18 or so when I did the water pump. Motorcraft replacement. To be honest I never really hear it doing much as far as making loud fan noises but, the A/C worked fine at idle or moving with that same fan and clutch setup until early 2020 when I yanked the compressor off and put the bypass pulley on, so I'm not saying the fan might not be part of the problem and will do some investigating on that. I've never liked these mechanical fan clutches because they are tricky to diagnose as bad compared to an electromagnetic clutch or electric fans. I can say it spins fine with the engine running and feels fairly viscous-y moving the blades by hand. The other thing is that the first time the pressure-relief valve puked a couple months ago while sitting in that rest area parking lot on a hot day, it didn't take but like 5 seconds from switching the compressor on the valve puking oil and gas. Yes, it was very hot under there...had been pulling a trailer in 85 degree weather and then sitting out in the sun in the truck parking area. My other question is whether the high pressure switch is working or not.

 

If you have doubts about the high pressure switch, just get a new one plus a plug repair kit and replace it. I'm on my third one now and the second plug repair kit. There's a check valve underneath it that will hold the AC charge when you remove the high pressure switch. It seems to be a common failure point.

 

Just a heads up if you decide to replace the high pressure switch with a motorcraft you will most likely have to get a new pigtail for it as they changed designs on the plug. Aftermarket still seems to have the same plug. This is what my local motorcraft dealer told me so I had them pull the part and sure enough the plug is not the same on the newer high pressure switches

 

For a beefier blast of cool air, you could also inspect your AC hoses for damage and ensure there aren't any leaks. Sometimes, the refrigerant tubes could also be blocked or compressed which affecting airflow. Furthermore, your air filter might need to be replaced if it's clogged up with grime or dust. Still, I'm not an expert here, so it's better to reach out to a hamilton air conditioner repair service.