a/c

Ok, got a brain teaser. My ac on my w900 won't cycle and the evaporative core in cab will freeze up after a while on the outside not internally. Checked freon level, it is good. Changed high and low pressure switches and thermostat switch. The compressor still runs all the time won't cycle. Any ideas?

 

All new, new dryer, new lines new everything. Only thing original is the condensor.

 

Yes it shuts off when I shut the a/c off. Works great cooling the cab. Just freezes up after a while. Turn it off and watch the drain poor water out as it thaws.

 

Yes stuck in the hole that is drilled in the tray.

 

This truck has always had a fluctuating gauge when I hook the gauges up. But not enough to worry about. I'm just wondering if I need to put a new condenser on. Thinking maybe there might be some debri floating around in the system that is screwing with the presume switches. Thought maybe I had a bad conection, but have ruled that out.