Ac question/issue - any help is greatly appriciated!!!

[Mpdevlin]

I'm pretty confident that I have all my wiring correct for the Factory Five supplied ac unit but here's my issue. My radiator fan comes on about 15 seconds after I turn the ac on but then shuts off. It keeps cycling on and off. On for 10 seconds, off for 15 seconds. its about 75 degrees here and I have a gauge reading of 45 on the low side and 175 on the high side. My first thought is that I don't have enough pressure in the system but both high and low are in spec. I don't want to just add more refrigerant without seeking some advice.

FYI the sight glass on the dryer is clear, no bubbles or foam.
Running a coyote and using the engine controlled fan. All of the tests that I've ran, the motor has been cold. Fan works as it should when the engine gets to operating temperature.

[edwardb]

These are my exact notes from when I charged the Factory Five A/C is my coupe 4+ years ago: "Gauge readings when done (at 70 degrees F and 24% humidity in garage): Static 84-85 PSI on both low and high. Normal listed as 80-105. While running: Low 18, High 180-250. Low reading seems a bit low, but everything else seems normal. High rises and falls as trinary switch goes on and off, including switching cooling fan on and off. Discharge air temp at vent: 43-44F. "

Notes entry from these year: "Update 05/31/2023: A/C seemed not as cold as last season(s). Connected gauges. Pressures looked OK but air temp discharge 50-55F. Connected new can of R134A. Seemed to take about 1/2 of the can. Pressures in range for humidity and temp. Discharge air temp at vent around 45F. Test drive and seemed colder."

Don't know if there's anything in there that helps. Would be useful to know what temperature you're getting out of the vents. That's another indicator of how the system is performing. Mine never cycled on and off as much as you're describing. Good luck.

[Mastertech5]

Is the compressor clutch cycling. on and off along with the fan? It should I believe. Fun the engine at 2000 RPM and recheck pressures. Outlet temp should be around 40 - 45 but will vary with ambient temp. and humidity. Low side pressure at 2000 should be in the area of high 20s to low 30s with the correct charge. You may have too much R134a in your system if it's at 45. You evacuated it with a vacuum pump for an hour (empty uncharged system) before you charged it right? They don't tell you that in the instructions.

[Mpdevlin]

Thank you for the input. I believe that the compressor is shutting off with the fan. I will check temp and run the engine at 2000 rpms and run some additional tests. Yes I did run a vacuum for over and hr and to evacuate the system.

[Mpdevlin]

Thank you for your input! I'm doing some additional testing.