A/C Gurus here's one for you
 

Last year I replaced all of the a/c components except for the evaporator core (flushed it thoroughly). Not long after that I had issues with the compressor cycling off and not coming back on. When the compressor is on the air is very cold, but if I change the temp setting or the air flow setting the compressor will quite working within a few minutes. The a/c will run for quite awhile if I don't touch it but will eventually quit. Could the be the pressure senor or possibly the control unit itself? any input would be appreciated.

might be overcharged - mine did similar work for about an hour then shut-down - i thought it was the hi-pressure cut-out switch, but turns out mine was overcharged and on really hot days would cut out after 20-30 mins - get a set of manifold gauges and check hi & low side or follow this guy's advice after you evac & prep to refill http://www.youtube.com/watch?v=PqNR7...e=channel_page

Did you do a proper evacuation? Could be moisture in the system- will cause a freeze up at the orifice tube and block the liquid refrigerant from flowing thru. Run the a/c until it quits and apply a heat source (heat gun works, or torch if you dare) to the line at the orifice location. If there is moisture in the system, the heat will melt the ice and refrigerant will begin to flow again for a while until the moisture finds its way back to the orifice again. If this is case, recover the charge, install a new receiver drier and immediatley evacuate to at least 750 microns (the lower the better- I like 250 microns, but it takes awhile), then carefully weigh in your charge. You may also want to think about how much oil you put in the system- too much will cause similar issues, but the compresoor typiclly continues to run, the system just loses capacity and doesn't cool as well. I am not an expert on vehicles, but I have been in refrigeration service for 23 years and own/maintain my fleet of 15 vehicles - all but two are Mopar!