Installing Classis Auto Air stage 1 AC unit and need clarification on the wiring at the AC compressor.
Two plugs went into the stock AC, two wires on flat plus in the front by the pully and two wires on round plug in the back.
Instructions state to cut the flat plug and use the green wire to connect to the red wire on the AC compressor.
The other black wire on this flat plug is not used. There is a black wire on the compressor but it is grounded to the case.
The round plug that went into the back of the old AC compressor (held by my fingers) should be cut and connected together.
For those who have installed this AC unit, please confirm this is the correct way to wire.
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Looking at your 1989 AC wiring diagram, the original compressor clutch had the black wire, which is ground, and the green wire, which is +12V to engage the clutch. Since your new compressor has only the red wire with no separate wire for ground, it must be getting it's ground connection through it's mounting metal to metal to the engine. So yes, disregard the black wire and connect the compressor's red wire to the car's green wire.

They are having you jump out the "AC High Pressure Switch" because presumably the new compressor doesn't have that. Yes, that will need to be jumped out for the compressor clutch to receive power. Personally I'm not in favor of removing what is essentially a safety device, but, , since I'm not the manufacturer for all I know they have provided a different means of protecting the system from over pressurization, a one time blow out valve perhaps, or maybe some kind of internal pressure regulator ?

(The diagram may look a bit confusing at first, but it's because they are including the wiring for the different engines used in 1989, hence the "VIN E", "VIN F", and so on)