Finishing up the radio installation from months ago, and can't remember where the radio wire labeled accessory goes. The stock wiring in the W123 was butchered, so have to hardwire. So, there is black, red, brown, and grey in what had a four pin connector, then a separate black wire. I am thinking it was doubled up with one of them. Does anyone know?

Thank y'all in advance!

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Current fleet:

1985 Mercedes-Benz 280TE - Waiting for heart surgery.

1985 Mercedes-Benz 300TDT - Rear ended 23 September 2016 and now looking for a new home.

1979 Mercedes-Benz 300TD - Parted out.

1964 Volkswgen Beetle - Vater's since September 1968 and undergoing a restoration.

1971 Volkswagen Sunroof Squareback with F.I. - in need of full restoration.

1971 Volkswagen Squareback automatic with F.I. - Vacationing with her caretaker until he is in better health.