My A/c will work for a few miles and then blow hot air. nothing will stop this until I turn off the ignition one notch and then back on (truck in neutral, coasting) and then it works fine all day.
Try replacing your cabin air filter. I know on some vehicles when they get dirty, it causes the A/C to to be intermittent. Here's a short how to video: http://m.youtube.com/watch?v=L37x4b35L8U
It is possibly just vacume line leak if it just doe,s it once in awhile.Check under dash at air box up to switch for leak,s.
Search Chevrolet Silverado 1500 Questions
Chevrolet Silverado 1500 Experts