K 2500 Suburban 4WD V8-5.7L VIN R (1999)
Trailer Connector: Description and Operation
Two trailer harnesses are available: the heavy-duty trailer towing (UY7) harness and the camper (UY1) harness.
Pickup Trailer Harness Routing
PICKUP TRAILER HARNESS ROUTING
Suburban/Utility Trailer Harness Routing
SUBURBAN/UTILITY TRAILER HARNESS ROUTING
The option UY7 trailer harness is for heavy-duty towing applications. A 30-amp fused battery teed wire and auxiliary circuit routes from the
cowl-mounted junction block, along the body side rail, to the rear bumper crossmember. The harness for the brake/parking lamps is spliced from the rear
lamp harness. The harness is at the rear bumper crossmember. A plastic strap binds the harness. Tape wrapped around the harness prevents short circuits.
The 8 wires have the following functions:
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Orange - The 30-amp fused battery feed
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Blue - An auxiliary circuit for electric trailer brakes
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Brown - The taillamps and the license lamps
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Light green - The backup lamps
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Dark green - The right turn signal and the stoplamp
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Yellow - The left turn signal and the stoplamp
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White (heavy gage) - Ground
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White (light gage) - The center high-mounted stop lamp
The UY7 option does not include a connector at the end of the harness. A qualified technician must wire the connector following production.
1. Attach the trailer harness wiring to the trailer
2. Strap the harness wiring to the vehicle in a manner that allows slack in order to prevent the following conditions:
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Bending
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Binding
