The cooling fan on the backside of the raditor comes on when air is turned on

Check your fuses. There should be a fan fuse in the fuse block either in the engine bay or under the dash on the drivers side. You might also find the a relay there also. When checking for power you just have to work your way back to the source. Trace the wires back from the fan. The power stops somewhere. i tried to find a schematic but couldnt find a good one to share. Buying a haynes manual may really help.