I've replace the compressor, condensor fan, condensor fan relay, hi/lo pressure switch, dryer and vaccuumed air out of the system. I applied 12 volts to compressor to fill with freon. When I turn the AC on, the condensor fan and compressor clutch won't engage. Any help is much appreciated. Thanks

 

Are you sure the freon is at the proper level? Im assuming you checked the system with gauges...not just one of those cans with a little gauge on the top. Assuming pressure is correct, check the pressure switch to make sure it is closed, when the system is on. I am thinkin it is a pressure issue. Anyway...if presure isNext I would check both relays(Compressor and condensor fan). When the system is off there should be 12V to one wire(The main wire, coil wire should be dead), when system is on there should be 12v to two wires. Now, check the relays...put 12v to the coil(Ground other side of coil) should pull in...you should hear click. The other two pins should now have continuity. That should get you started