So my a/c compressor is turning on and off so i did a pep boys recharge and still the same thing, any ideas? Also when it is on it makes a squeaking squealing sound there's a few thing it could be, sensor, clutch, compressor by how can i figure what it is without guessing?

 

We need a bit more contect.

The a/c compressor is supposed to "turn on and off". Thats how the clutch on it works. It doesnt run constantly when you have the a/c on.

What are the actual issues with it? We can't help you without guessing either....

 

i know its supposed to turn on and off obviously but not every 5 seconds to keep cycling on and off

 

low pressure = no turn on
high pressure = cycling of compressor rapidly as the high pressure switch cuts in .

reduce charge until compressor does not cycle on and off constantly anymore.

What I would do is evacuate the system with a vaccum pump, verify that it hold's a vaccum for at least 4 hours and then recharge with proper amount of PAG oil and R134a

 

Is the a/c still blowing cold air? Is this only at idle? When you had the a/c serviced, did they check the pressure, and if so, what was it?

EDIT - What YeuEmMaiMai said. It sounds like theres too much freon in the system.