I am new to the board but I have a question. I have a 2000 dodge diesel that the ac is not blowing cold air. Because I gradually lost cold air a couple of years ago people told me that I had a leak and just needed new freon. Well put it on a gauge today and that is not the problem but the conpressor will engage and the pressure will come up till it gets just a little in the yellow and then will shut off and the pressure will go down then it will kick back in. What would be causing this and is there a easy (cheap) fix.

 

Do you have actual gauge readings. Not sure what yellow is but there are two switches to cut out the compressor. 1 is a low pressure switch to cut the compressor out when the lowside gets to low and the other cuts out the compressor when the highside pressure gets too high. With the a/c on, feel the a/c lines. the line coming out of the compressor to the condensor should be hot. The line from the condensor to the orfice tube should be warm. From the orfice tube to the evap should be cold. Out of the evap to the accumulator and from the accumulator to the compressor should be cool.