A/c help

Before you start dumping more refrigerant into it, find out WHY it is short cycling.

Could be the control, a bad low pressure switch, low refrigerant, water or other cantaminnants in the system can allow the metering device to plug/ thaw etc

"New" parts does not mean "good, functioning" parts"

The fact that temp goes on down when you bypass the controls almost sounds like a control problem rather than a system problem, but you need to check operating pressures and temps to find out. (Too little refrigerant is as bad as too much, either can damage the compressor)

Since yours is a 72 (You still run R12?) you can download the factory manual right on this site

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

And, the guy at MyMopar posted some Ma service videos, which I posted here the other day:

http://www.forabodiesonly.com/mopar/showthread.php?t=185055

Here's the link to the master Youtube page, there are over 200 videos on Ma service

http://www.youtube.com/user/mymopartv#g/u