Nissan Repair: 99 sentra ac problem, coolant level, radiator fan

Question
My ac in my 99 sentra blows hot air when i turn it on. I bought refrigant but when iput the gage on it says its full. An also when i turn on my ac it bogs my engine down and i lose all power in the car, and if it sets still to long it overheats until i pull off. If you have any idea to what my problem is id greatly appreciate it.
Thanks, michael

Answer
Hi Michael, one of the reasons, it could be too much refrigerant in the system. The other reason, it could be a failed clutch/pulley assembly or a bad compressor.
Disconnect the negative battery terminal for safety. Loosen and remove the belt that drives the a/c compressor. Spin the compressor's pulley by hand. It should spin freely without any grinding noise and without any play. Now try to turn the clutch by hand. It's hard to turn it but it should turn. If it doesn't, then the compressor is bad or it has way too much refrigerant in it. In both cases, the engine has to work much harder to turn the compressor and as a result it runs hotter and loses power. Now, there are other reasons that will cause the a/c to blow hot air, like prevention of the clutch to engage due to a failed low pressure valve, physically or electrically. And there are other reasons that will cause the engine to overheat when the a/c is turned on, like radiator fan failure, low coolant level in the radiator and other failures of the cooling system, but these do not bog down the engine.
Hope this helps.