Please move this if I’m in the wrong area.

2001 Ranger 4.0

My ac compressors clutch will continuously engage and disengage, staying between 100-120 psi on the high side, and the low side will vary depending on how much 134 is in the system. I’ve already checked the high and low pressure switches, and can’t think of what would cause the compressor to function only to a certain point?

 

Pressure chart here: https://www.acprocold.com/wp-content...rt-33776F1.jpg

What was the outside temp during the pressure tests?

 

it was about 90F in my garage.

 

So your high side should have been at least 250psi, not 120psi
Low side should have been 45psi

 

https://youtu.be/7IIvD9PiFoc

here’s a video of what is happening. Clutch will engage and pressure will clime, and the clutch will immediately disengage. Both pressure switches are functioning properly, and I’m not sure what the next thing to check is. If I send power to the clutch manually it’ll stay on just fine.

 

If pressure climbs then compressor is working and if high pressure switch opens(turns off compressor) then either the switch is bad or system is blocked, pressure can't get out thru expansion valve and return to low pressure side of system
High pressure switch prevents systems connections from exploding if pressure exceeds their range

Or if low pressure switch opens(turns off compressor) then it may be bad or system is blocked so fluid can't flow back to compressor
Low pressure switch prevents compressor from "running dry" which would cause it to burn out

The fluid circulates thru the system, the pressure tells you how well its circulating
If the high pressure keeps going up and the low pressure keeps going down then there is a blockage