A/C now it works now it doen't

I have a 98 Montero and for some strang reason my a/c works sometimes and other times it does not. When I start the car it works then after 10 - 30 min. it will stop working. t just blows hot air. The problem is it only happens every once in a while. And when I turn the car off for more then 1 hour it will work again. Every time I have free time to get it to a mechanic it works so they can't find the problem. I did get it there once. But they turned the car off to go to lunch and when they turned it on after lunch it worked. Has this happend to anyone? Or can anyone think of why this happens?:banghead:

Is your engine overheating? IIRC, there's a thermal cut-off switch to prevent damaging the engine when it's overheating.

related to offroader's post, try to check the fans as well if they're working or not.

you did mention that the aircon goes back after you've cooled the engine a bit, so it does point to heat-related issues.

i had the same problem i changed the expansion valve and that cured the problem