Add me to this list. We bought two Tahoes at the same time. On delivery day, my wife's A/C wasn't working. They took it back and fixed it, no idea what they did. Then yesterday, with 600 miles on my Tahoe it worked fine for my trip home from work to the daycare. I picked up my son, turned on the truck and the A/C blew hot air for about 3 or 4 mins before it kicked on. If it happens with any regularity I'm going to have to take it in.