I went to talk to a Dealer service rep. today. He says they need to evac. my system because it prob. has low pressure and will cause this to happen. He said I prob. have a leak!! I doubt this because it has done for the last 2 years and the driver side bolws cold. I have to run on recirulate all the time get some cold air out of the passenger side. I have a '05 hvy.duty diesel. These dealers crack me up. I just don't know where to take it.! Any help would be appreciated. He also said this only happens on the trucks!??

 

It's very common in the dodge. The plastic doors in your heating and air flow system in the dash are probably bad. I had to replace one in my 03 last year. The door has a plastic piece that comes faulty from the factory. Do a search, there are a lot of articles and detailed instructions as to what to look for.
Chris

 

Actually, they're correct in their diagnosis. I just went through this a couple months ago, same symptoms, and they evacuated and recharged the system. Now it blows 38* on both sides. They also injected the dye to look for the leak.

 

I had the same problem. Just evac and recharge the system like they said and it will fix it. I just added some to mine from the local parts house recharge kit and it worked too but the correct way is to evac the whole system and recharge.