Trailer Wiring HarnessYour vehicle may have a seven-wire trailer towing
harness. This harness may have a seven-pin universal
heavy-duty trailer connector (if equipped with the
trailering package) that is attached to a bracket on the
hitch platform or included with the four-pin trailer
towing harness. If your vehicle is not equipped with the
heavy-duty trailer connector, you may purchase one
from your dealer. The seven-wire harness contains the
following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
Light Green: Back-up Lamps
Dark Blue: Electric Brakes
Red: Battery Feed (The chassis wiring ring terminal
must be fastened to a stud on the underhood
electrical center before the trailer feed will become
active.)
If you need to tow a light-duty trailer with a standard
four-way round pin connector, an adapter connector is
available from your dealer.
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If you are charging a remote (non-vehicle) battery, turn
on the headlamps to boost the vehicle system voltage
and properly charge the battery.
Your vehicle is also equipped with wiring for an electric
trailer brake controller. These wires are located
inside the vehicle on the driver’s side under the
instrument panel. These wires should be connected to
an electric trailer brake controller by your dealer or
a quali ed service center.
Your vehicle may be equipped with a four-pin trailer
towing harness. This harness has a four-pin trailer
connector that contains the following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: GroundThis harness also contains the following trailer circuits
that are not connected to the four-pin trailer connector:
Light Green: Back-Up Lamps
Dark Blue: Electric Brakes
Red: Battery Feed
If your vehicle is a TrailBlazer SS, you were provided with
a trailer wiring harness extension, and instructions for
installing this extension, when your vehicle was delivered.
This extension will allow your vehicle’s trailer wiring
harness to be more easily accessible. There is a four-way
connector on the harness. A seven-way adapter plug is
also included in case your trailer requires it.
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