2003 Highlander V6 Help

Wife's air conditioning is not working as it should. It will blow cold then warm. I checked under the hood and noticed the compressor cycling on and off and at the same time the 2 fans would do the same thing when the ac went on and off. I went and tried more freon and found out you could over pressurize the ac and it will not work. That happened to me so I let some freon out. Well the compressor is back to doing the same on and off. Might stay on about 10 seconds at a time then off. Is there some sensor on the compressor that might cause this? Or does the compressor work this way on and off. I do recall that in other cars the compressor will stay on and if the car temp gets too hot the fans will come on. Not at the same time the air is put on. Any suggestions on the compressor I did check for leaks and there seems to not be any leaks.

thanks

the compressor should not be cycling that fast that is an indication that the system is low and the compressor is trying to pressurize the system but there is not enough ref. to pressurize the system. More than likely you have a leak all it take is a tiny pebble to hit the condensor just right and the hole may be too small to see without the use of uv dye. You are right in the fact that if you use one of those cans of ref. you get at a parts store you can over pressurize the system because you have no idea how much ref. is in the system best thing you can do is take it in to be looked at by a certified ac shop hope this helps