My AC works, it blows nice cold air. The guy I bought the car from had put in a new AC Compressor, probably by himself. The problem is, my compressor kicks on and off and on and off constantly! Probably about 4 to 5 seconds between the on and off stages. It is really annoying, it causes the RPMs to go up and down when it happens. What do you think the problem is??

 

Sounds like you could be low on refigerant. If you have access to a set of R-134a guages, check your high and low side pressures. The manual says with the engine at 200 RPM, low side should be roughly 30-45 PSIG, depending on temp & humidity. High should be roughly 160-350 PSIG, depending on temp & humidity. These numbers are for R-12, but should be almost the same for R-134a.