Get a set of A/C gauges and hook them up to the system. You may need to borrow some hoses to get the gauge manifold in the cab with you. Get going down the road and observe the pressures--the pressures will tell you exactly what is going on. If you build high side pressure, you will see at what pressure the trinary switch cuts the compressor out and can see if it is functioning properly.

Remember 9-11-01--God Bless the USA
JUSTICE, not REVENGE, will prevail

1951 Chevy 1/2-ton Pickup truck