GMC Chevrolet Express 2022 Owner's Manual page 162

Tires must be properly inflated to support
loads while towing a trailer. See Tires
0 192 for instructions on proper tire
inflation.
Safety Chains
Always attach chains between the vehicle
and the trailer, and attach the chains to the
holes on the trailer hitch platform.
Instructions about safety chains may be
provided by the hitch manufacturer or by
the trailer manufacturer.
Cross the safety chains under the tongue of
the trailer to help prevent the tongue from
contacting the road if it becomes separated
from the hitch. Always leave just enough
slack so the combination can turn. Never
allow safety chains to drag on the ground.
Trailer Brakes
Loaded trailers over 675 kg (1,500 lb) must
be equipped with brake systems and with
brakes for each axle. Trailer braking
equipment conforming to Canadian
Standards Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State or local regulations may require the
trailer to have its own braking system if the
loaded weight of the trailer exceeds certain
minimums. These requirements vary from
state to state. Read and follow the
instructions for the trailer brakes so they are
installed, adjusted, and maintained properly.
Never attempt to tap into your vehicle's
hydraulic brake system. If you do, both the
vehicle anti-lock brakes and the trailer
brakes may not function, which could result
in a crash.
Trailer Wiring Harness
Basic Trailer Wiring
If the vehicle is not equipped with a trailer
connector on the rear bumper, a seven-wire
trailering harness is tied to the vehicle s
frame. The harness requires the installation
of a trailer connector, which is available
through your dealer.
Use only a round, seven-wire connector with
flat blade terminals meeting SAE J2863
specifications for proper electrical
connectivity.
The seven-wire harness connector contains
the following trailer circuits:
Yellow: Stop/Turn Signal Left*
Driving and Operating
Dark Green: Stop/Turn Signal Right*
Brown: Tail/Parking Lamps**
Light Green: Reverse Lamps**
Red/Black: Battery Feed
White: Ground
Dark Blue: Electric Trailer Brake
* If the vehicle is a cutaway with trailer
provisions, each stop/turn signal has a
15 amp fuse. However, the cutaway lighting
connector will have a 10 amp fuse for each
signal.
**If the vehicle is a cutaway with trailer
provisions, there is a 15 amp fuse for the
trailer park lamps and a 15 amp fuse for the
cutaway rear lighting connector park lamps.
Also, a 10 amp fuse will be shared for trailer
back-up lamps and cutaway rear lighting
connector back-up lamps.
Heavy-Duty Trailer Wiring Harness Package
lf equipped, the trailer wiring harness, with
a seven-pin connector is mounted on the
trailer hitch.
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