I have a nissan frontier 2001. a few months back the ac went out. turns out a hose was cracked, so we had it replaced. All was well since.
This past week the brake light started coming on, so I topped of brake fluid and the light went out. Now, my ac works sporadically. Sometimes it blows ice cold, then all of a sudden it feels like just the fan is on. Its hit or miss on the ac. I had an ac shop check into it, but couldnt reproduce the problem there. Of course once we are at the ac shop the air blows cold. The mechanic said it must be a wireing short somewhere and couldnt help any further.
Anyone else have any ac problem like this? Theres plenty of freon in the system.

 

I have a 2001 Nissan Frontier 186,000 miles 4 cyl 5 spd XE with the same problem. Air from the vents with AC off sometimes is 20 degrees hotter than ambient. AC will sometimes freeze me and other times feels hot. I am about to disassemble the duct work to see if anything foreign is in there. Any other ideas?

 

IT might be the intake sensor switch causing it to cool and then stop cooling.