2000 nissan altima a/c some times it works and sometimes it don't.The freon was checked and was full,It works good when it works ,The clutch seams to work properly when it come on ,but it come on when it wants to.

a/c comes on the goes off I check freon was good, one day it works fine next day don't work at all.I was told that it good be a thermo amplifier. Could this be the problem.

Thanks jim