Ford Repair: air conditioning, test light, ac compressor

Question
I have a 1993 ford explorer, and when i push the air condition button in and turn on the blower, nothing happens. I open the hood to the truck and the clutch is not turning and no cold air is coming out of the vents. I would like to know if this could be the relays or the compressor.
thank you
Ernest Freer

Answer
Its probably the clutch on the compressor if it does not engadge when you turn on the control.  The only way to test it is to put power directly to the clutch.  Consult a electrical manual on which wire coming from the AC clutch is the ground, which is positive, and any others that may be on it.  A way to test the wiring is to remove the plug from the AC compressor and use a test light.  Attach the test light to the ground, stick it in the terminals on the plug and turn on the switch.  Test them all.  If the light fails to turn on, you know that the wiring and the switch is the problem.