A/C Compressor Won't Kick On

I've got the system ready to charge with 134a, and I can't get the compressor to kick on..........The wire from the compressor hecks out as far as I can get to the edge of the firewall......no problems........

Fuse is OK, BUT in my wiring diagram, I note that the heater runs off the same fuse....AND, there is an inline resistor for the heater.......

Question: Does the A/C compressor use a resistor also?........or does it run off straight 12V dc?................If it runs off straight 12V, I could rig a switch for now until I can tear the dash apart and do it correctly.......don't want to blow anything though......I don't see any sort of relay in the diagram either.

Can that compressor be wired directly to a heavy duty switch for now or not?

Need a fast answer.....if you can shed light, point it this way! :read2: