Here's an 80-80 F-series truck diagram

1980-81 Ford F Series Stereo Information
Constant 12V+ Light Green
Switched 12V+ Yellow/Black
Ground Chassis
Illumination Blue/Brown
Dimmer n/a
Antenna Trigger n/a
Antenna Right Front
Front Speakers 5 1/4" Doors
Left Front (+) Green
Left Front (-) Black/White
Right Front (+) White/Red
Right Front (-) Black/White
Rear Speakers 6" x 9" Rear Corners
Left Rear (+) n/a
Left Rear (-) n/a
Right Rear (+) n/a
Right Rear (-) n/a