There's a good write up here. Search, Dodge Ram a/c compressor clutch at About.com auto repair. Problem is you have to buy a whole new compressor to get the clutch and coil. Looked like your gauge was up in the red at very beginning of video? Does it blow cold and clutch stay engaged while parked and idling?

 

I think you are correct.

 

It does fine at idle, pressure seems to be in on range, but when you give it gas the ac compressor clutch kicks off and the pressure shoots up.