You said you are running 300 PSI on the high side. Although the system can handle that pressure at 75-80 F or so, it should be closer to 40-45 on the low side and 150-165 to 225-250 max PSI on the high side. Who did the work or add refrigerant to your A/C system?

 

Never said my high side was 300.

 

My mistake.My apologies for that..

 

Today I connected the fan myself with a switch & inline fuse. The fan will reverse direction if the blue/black wires are interchanged but I have it connected to blow air through the condenser toward the radiator (same direction as radiator clutch fan). With the fan running at idle for 1-2 minutes the a/c air temp is not getting colder so it was a waste of time. If I rev up the engine to 2000 rpm for 30 seconds or more I can feel it start to cool down, with or without the electric condenser fan on, but that's a much bigger fan pulling air.

 

r the fan shrouds in place...they gotta be there or the fan won't cool ship

 

You might be thinking inside a box. Have you thought about using an infrared tach to see if your compressor clutch is slipping? You should be getting liquid freon at idle if the compressor isn't cycling.