I know this is an old thread, but I am going to resurrect it. I took my 05 Tahoe in last year because of the same issue, only reverse. I had both controls for the front AC turned all the way down to 60. Cold air was coming out of the driver side, super hot air out of the passenger side. They replaced the actuator on the passenger side, I assume it was with a Dorman. Like MO VietVet said, and I quote... "Do Not... I repeat, Do not use Dorman!" So I'm on my way to Greensboro, NC this evening with the wife and guess what, back to the same old issue. Cold air on the Drivers side, super hot on the passenger side. It has to be the actuator so I am going to get an AC Delco tomorrow from the dealer and install it myself. I know I have seen several How-To vids out on YouTube so I'm going to give it a shot. The only thing I'm concerned with is the price of the actuator...