2000 Nissan Xterra AC Problem
 

I have a 2000 Xterra and my air conditioning only works if it is on the highest setting. I have changed out the knob and that is not the issue. Any suggestions? Is this an electrical issue? Any advice would be greatly appreciated before I am forced to take it somewhere and spend a lot of money.

maybe the aircon itself is the problem... change your aircon and install new one.