Hey Mike, good to see you on the forums again!

Thanks for the tips, I will try these things. Yes, some other forums suggested the ground/ampsense are the center pin and one below, leaving audio as the "outside" four.

I had my voltmeter set at 12V to test. I got a 9V signal from the center pin and nothing from the others. My voltmeters only have ranges of OHM, DCV, DCA, ACV, so I thought DCV 12V was the only one to use.

I tried grounding to the outer ring, but I'm testing the female end of the connector, so I'm not sure where the contact is for that. I'll keep checking.

Thanks again, I'm sure this is possible.