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When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) (or
the manual transmission out of gear and the parking
brake applied) for a few minutes before turning the
engine off. If you do get the overheat warning,
seeEngine Overheating on page 5-29.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet, or into gear for a manual transmission.
When parking uphill, turn your wheels away from the
curb. When parking downhill, turn your wheels into
the curb.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P), or
REVERSE (R) for a manual transmission. See
Parking Brake on page 2-32for more information.
5. If you have a four-wheel-drive vehicle, be sure
the transfer case is in a drive gear and not in
NEUTRAL. SeeFour-Wheel Drive on page 2-28
for more information.
6. Release the regular brakes.
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When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. SeeScheduled Maintenance on page 6-4
for more on this. Things that are especially important in
trailer operation are automatic transmission uid (don’t
over ll), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you nd them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
If your vehicle is equipped with a trailer towing package,
the rear bumper harness will have a seven-pin
universal heavy-duty trailer connector attached to a
bracket on the hitch platform.
The trailer towing harness contains the following seven
trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
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White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Trailer Brake
If you are charging a remote (non-vehicle) battery, turn
on the headlamps to boost the vehicle system voltage
to properly charge the battery.
Trailer Brake Control Wiring Harness
The wires for the trailer brake control are taped to a
wiring harness under the instrument panel. The trailer
brake control harness will contain the following
labeled wires:
Dark Blue Wire (#47): Trailer Brake
Red Wire (#242): Batt ‘‘+’’
Light Blue Wire (#20): Brake Lights
Black Wire (#2050): Brake Ground
Trailer Recommendations
You must subtract your hitch load from the CWR for
your vehicle. Weigh your vehicle with your trailer
attached, so that you won’t go over the GVWR or
the GAWR.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, seeTowing a Trailer on page 4-44
later in this section.
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