Sound from compressor

I just recetly bought this car. I live in Alabama so even in Feburary soometime I need to run the a/c. The problem is that when I turn on the a/c switch on the climate control panel, the compressor turn on for 2 or 3 seconds and then cycles off then about 6 seconds later it turns on for 2 or 3 seconds and cuts off. This will repeat for as long as the a/c is on. During the on cycle it gets cold and actually if you are driving a long distance at highway speed it keep sthe interior cool.
I figured that it was a little low on freon so I bought one of those top off cans with the guage and it says that the freon is full (green zone). Could a faulty low pressure switch cause this problem? Does my vehicle have a low pressure switch? (I have inquired at a number of local part shops and no one shows a low pressure switch for my car.

Any comments would be appreciated.
Philip Hebbler
Fayette, Alabama

Air Conditioning problem
1999 Mazda 626 4 cyl Two Wheel Drive Automatic 136000 miles

I have checked the charge on the system and it is within the specified limits. I think I may have a problem with the low pressure switch. Can you tell me where it is located and how to test and/or repair it?

I don't have the specific information on the location of the low pressure switch-it should be a two wire switch located close to the dryer or condensor, in the front of the car. The wires will be pretty hefty. Also check the air gap between the a/c clutch and compressor--too great a gap will also give you the symptom you are describing. Maybe someone else on this forum will have the specs for testing switch and air gap--my mitchell manuals are in the mail as we speak, so I don't have them in front of me. As an alternative, you can sign up to all data or mitchell on demand, a month's or even a year's subscription for your specific car is as low as 20 bucks. Lots of good info and all the specs, far superior to anything except the factory manual. Good luck

AC compressor will only run on 2 of the 4 Slider switch positions. The fan will only run on the other 2 of 4 switch positions. The AC aand fan will not run together on any of the positions.

I do not know if or were the fan module/ resistors are located. This fault occurred after a mechanic installed a replacement alternator.