You will have to be more specific... what controls did you fiddle with?
Does the compressor run at all?

Professor
Check out FlashAlert at www.telstar-electronics.com

My 2000 Frontier was having simillar problems last year. Would blow cold
then not.
If I turned it off then on it would get cold again, sometimes. I took it to
a local shop who wanted to replace everything.
I was sceptical of this since it would be cold when it worked. They wanted
$1500 and I hadn't made my first payment.
I went to the dealer and the manager said it was the "thermistor". I had no
idea what this was but the dealer covered it.
Moral of my story is the local shop wanted to replace everything but the
problem.
Good luck mesa, Maxxer