What would make an air conditioner on a 2000 Nissan Exterra work intermttenly?

Check the following...........

1. Freon level in the system.

2. Power and ground going to the a/c clutch.

3. Clutch front hub air gap.

4. Pressure switches.

5. If the freon level is fine on both the low and high sides it will be a lot easier to just scan the vehicles computer and see what is going on.....