My 1972 wiring diagram indicates a pink wire that supplies +12V to the ballast resistors and coil, it could be used to supply the key switched +12V. The pink wire also connects to a red wire that connects to a throttle solenoid as well. I have used this lead for my add-on's and modifications.
Are you sure the A/C connection is to operate the A/C compressor? I cannot see why, I would think that the A/C connection is to increase the idle speed when the A/C is turned on, therefore it would be an input to the Gen 7. Most modern cars increase idle speed and even have an input from the power steering pump to increase the engine speed during parking.
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