A/C problem

[CMcDonald]

I have an A/C problem that I need help solving. My truck will blow vent temperature air out of the passenger side vents about once every 2-3 minutes. My truck is the SLT without dual zone controls. This happens on regular air and also on max but it is not as noticeable. A tech rode with me and there is about a 10-12 degree difference. The outside temp has to be at least 78 for it to do it. The dealer has been working with me. They have replaced the blend doors and even slightly overcharged the system. The drain from the condensor flows like a waterfall under the truck. On hot days I cant get the temp below 50 on regular air. I have seen this is a common problem from this web sight as well as other Dodge web sights. Any suggestions?--- Thanks