Wiring diagram for 69 b-body rear speaker fader

Hey gang... Been looking in my FSM and can't see a wiring diagram for the rear speaker with fader configuration. It shows the 8-track 3-speaker with fader, but just the rear speaker with fader.

Looking to see if my intermediate harness is useable need get a complete harness. Would hate to just put the 3speaker harness in and waste it by using only the middle front main speaker.

Thanks...

Can you post a picture? generic faders were typically 3 terminals, 1 for input, the other two for front and rear speakers. it gets a bit cloudy on the wiring for the ground side with some using a common chassis or teeing into the radio ground.
Others would have 6 terminals, two in, and two out for each speaker.