96 ram 1500 4x4 slt - a/c wouldn't do anything. added some freon. compressor started to cycle. compressor now cycles on for a few seconds then off again. the low pressure side gets cold but not cold enough.

put a jumper in the low pressure switch to force the compressor to continue to run. added more refrigerant. low pressure is now 25 and high pressure is 125 (The hi pressure gauge has been laying around for years and may not be accurate). The air will blow cold for a while but then starts to get warm - probably freezing and needs to cycle.

Could it just be the low pressure switch? I would just go get one and try it but I have company and can't get away.

 

If you added a sufficient amount of freon, you may be experiencing expansion valve clogging (where the valve gets smaller over time from gunk and will not allow the rapid expansion of freon like normal).

1. How much freon did you add?
2. When you remove the jumper how long will the compressor stay on?

 

If at idle, the compressor kicking on and off then on and off is normal.

+1 for gobbell1's questions.

 

It's probably leaking out the evap core as fast as you put it in. Bring to an AC shop and they will use a freon leak detector .

 

I hope it isn't the evap core leaking. Do the pressures (25/125) appear normal? I have a leak detector at work I can bring home.

 

If the compressor continues to cycle on and off then the evap core isn't leaking otherwise the lowside switch would cut out the compressor all together. I second the expansion valve being a possible source of your problems. Sounds like the expansion valve needs to be replaced followed by a fresh charge. Make sure your condensor isn't all filled up with debris in the fins.