Okay I'm planning on swapping the entire A/C setup from a donor 1994 4runner into my 1986 4runner. All I need from it is the compressor, the hardlines, and all the stuff in front of the radiator. Then run the lines into my condenser box I already got from a donor 1st gen 4runner. Can I not just simply wire a switch to the compressor clutch and the small fan in front on the rads? Or is it more complicated? I can honestly just keep an eye on my coolant temp and turn it off when needed.

 

There are universal A/C units out there for many types of vehicles that have switches directly on the unit. I would think as long as you have air flow across the condenser and your switch engages the evap blower motor and A/C clutch it should work. You might not have an idle up feature with your setup? The thermal bulb on the expansion should keep it from freezing up and hopefully you have a high pressure cutout switch and a low pressure switch in the circuit.