Having Issues With The A/c On 2008 Nbs

[chevinator]

The A/C blows on all four vents in the front cabin but the two on the drivers side blow hot to warm air. I have a 2008 1500 EXT Cab 5.3. The problem occurs at least once a day and has become more frequent. I also noticed and dont know if its somehow tied in that on some occassions the remote start wont work. I took it to the dealer but on that day it didnt act up and the tech said he didnt find anything, the service rep. told me the next time it happened to come back but its usually after I get off work and the dealership is closed. Just checking if anybody has had similar problems. Thanks!