Chevrolet 1998 Express Van Owner's Manual page 200

Trailer Wiring Harness
The light-duty trailer wiring harness is a six-wire
harness assembly. The optional heavy-duty trailer
wiring package is an eight-wire harness assembly. The
harness is stored under the vehicle, along the driver's
side rear corner of the frame rail. The heavy-duty trailer
wiring harness has a 30-amp feed wire. Both harnesses
come without connectors and should be wired by a
qualified electrical technician. The technician can use
the following color code chart when connecting the
wiring harness to your trailer.
Dark Blue: Use for electric trailer brakes (eight-wire
harness only)
Orange: Trailer accessory (eight-wire harness only)
0
Light Green: Back-up lamps
0
Brown: Parking lamps
Yellow: Left stoplamp and turn signal
0
Dark Green: Right stoplamp and turn signal
0
White (heavy gage): Ground wire
White (light gage): Center high-mounted stoplamp
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. Store the
harness in its original place. Wrap the harness together
and tie it neatly so it won't be damaged.