Trailer Wiring Harness
Your 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.
If you are charging a remote (non-vehicle) battery,
turn on the headlamps to boost the vehicle
system voltage and properly charge the battery.
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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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