Radio installation I ned to find the wiring diagram for 1988 S10 radio, what the colors go to.

1985 Chevrolet S10 Pickup Truck Car Stereo Wiring Diagram
Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 4′ x 6′
Car Audio Front Speakers Location: Dash
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Rear Speakers Size: 4′ x 10′
Car Audio Rear Speakers Location: Rear Corners
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

You can also go to BestBuy and purchase a wiring kit for your radio/cd that will fit your truck. ( I assume you are switching out the old one with new) It comes with the plugs/connectors and a diagram to install. Made life easier for me when I installed a CD player in my 88 s-10