ac compressor plug?

[shmed]

ok. there's a. 2 prong plug at the front bottom of the compressor   I believe its for the clutch to lock up. anyways which way does the connector go on?  there's a green wire and a black
thanks

[Steve Wood]

http://www.vortexbuicks-etc.com/ac_compressor_electrics.htm

The clutch connector is green and black as you said.  The black side goes to ground thru the high pressure switch on the compressor as the diagram shows on the diagram.  That switch should normally be closed so you can find ground with your meter.  

The connector that goes to the compressor should have a diode wired across it as shown on the diagram.