A/c there is power in

You're definitely going to need to check to see if you have Freon in the system because like james12b said, pressure switches are key to allowing the A/C clutch to get its power.

If you get a repair manual you will find that there is a single 4 wire connector on the a/c system that attaches to the pressure switch and for service you need to remove the connector and then short the proper wires to fool the system into thinking the pressure condition has been met. Then you can test the cluth by turning the a/c on (with the engine running but only very briefly if it the sytem is not properly charged) just to see if the clutch actuates and the compressor starts to spin (which is sort of only detectible by system rest to operating pressure changes). But that way you can at least know that the a/c clutch is good.

However, until you charge the system and find no leaks can you determine if the compressor is really still good. Of course, if you find leaks then first and foremost you have to fix those and, as a home do it yourselfer, you'll have to do an r134a conversion and even if you get it all good to go, it won't work as good as the original r-22 system but only a professional can legally work on the system with r-12 or r-22 anymore (not to mention legally purchase those refrigerants).

For my 88 Escort GT, I could never get past the fix the leaks part because I could never get the very discernable leaky connections apart, even with the right quick disconnect tools and everything. I just couldn't get the right leverage where the bad connection was as it was just too tight to work with my big fat hands and I think the o-rings were all hardened up and fused to the pipes and wouldn't budge unless I could put my whole body and not just wrist into it. FORD is very bad about things like providing adequate after market servicing space (see crank shaft pully problems people have for instance).

There are switches and things with parameters that must be satisfied before power is supplied to the compressor clutch. First you must request a/c by turning it on. Then the high and low pressure switches have to be satisfied, the engine cooling fan must come on(if it is an electric fan) and then she should run. Thats the general idea, but a specific wiring diagram to your vehicle would help.