2007 HUMMER H2 trailer

But let’s say your specic vehicle is equipped with
some of the latest options and you have a front seat
passenger and two rear seat passengers with some
luggage and gear in the vehicle as well. You may
add 300 lbs (136 kg) to the front axle weight and
400 lbs (181 kg) to the rear axle weight. Your
vehicle now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you
may think that you should subtract 700 additional
pounds (318 kg) from your trailering capacity
to stay within GCWR limits. Your maximum trailer
would only be 7,800 lbs (3 538 kg). You may go
further and think you must limit tongue weight
to less than 1,000 lbs (454 kg) to avoid exceeding
GVWR. But, you must still consider the effect
on the rear axle. Because your rear axle now
weighs 3,100 lbs (1 406 kg), you can only
put 900 lbs (408 kg) on the rear axle without
exceeding RGAWR. The effect of tongue weight isabout 1.5 times the actual weight. Dividing the
900 lbs (408 kg) by 1.5 leaves you with being able
to handle only 600 lbs (272 kg) of tongue weight.
Since tongue weight is usually at least 10 percent
of total loaded trailer weight, you can expect
that the largest trailer your vehicle can properly
handle is 6,000 lbs (2 721 kg).
It is important that you make sure your vehicle
does not exceed any of its ratings — GCWR,
GVWR, RGAWR, Maximum Trailer Rating
or Tongue Weight. The only way to be sure you
are not exceeding any of these ratings is to weigh
your vehicle and trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the
upper limit for cold tires. You’ll nd these numbers
on the Certication label at the rear edge of the
driver’s door or seeLoading Your Vehicle on
page 362. Then be sure you don’t go over
the GVW limit for your vehicle, or the GAWR,
including the weight of the trailer tongue. If you use
a weight distributing hitch, make sure you don’t
go over the rear axle limit before you apply
the weight distribution spring bars.
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Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads
are a few reasons why you’ll need the right hitch.
Weight-Distributing Hitches and Weight
Carrying Hitches
When using a weight-distributing hitch, the hitch
must be adjusted so that the distance (A) remains
the same both before and after coupling the
trailer to the tow vehicle.If you will be pulling a trailer that, when loaded,
will weigh more than 5,000 lbs (2 268 kg) be sure
to use a properly mounted weight-distributing
hitch and sway control of the proper size.
This equipment is very important for proper
vehicle loading and good handling when driving.
You should always use a sway control if your
trailer will weigh more than these limits. You can
ask a hitch dealer about sway controls.
Safety Chains
You should always attach chains between your
vehicle and your trailer. 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 you can turn with your rig. Never allow
safety chains to drag on the ground.
(A) Body-to-Ground Distance (B) Front of Vehicle
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Trailer Brakes
If your trailer weighs more than 2,000 lbs (900 kg)
loaded, then it needs its own brakes – and they
must be adequate. Be sure to read and follow the
instructions for the trailer brakes so you’ll be
able to install, adjust and maintain them properly.
Your trailer brake system can tap into the
vehicle’s hydraulic brake system only if:
The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
The trailer’s brake system will use less than
0.02 cubic inch (0.3 cc) of uid from your
vehicle’s master cylinder. Otherwise,
both braking systems won’t work well.
You could even lose your brakes.
If everything checks out this far, make the brake
tap at the port on the master cylinder that
sends the uid to the rear brakes. But don’t use
copper tubing for this. If you do, it will bend
and nally break off. Use steel brake tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint
yourself with the feel of handling and braking with
the added weight of the trailer. And always
keep in mind that the vehicle you are driving is
now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer
moving and then apply the trailer brake controller
by hand to be sure the brakes are working.
This lets you check your electrical connection at
the same time.
During your trip, check occasionally to be sure
that the load is secure, and that the lamps and any
trailer brakes are still working.
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Following Distance
Stay at least twice as far behind the vehicle ahead
as you would when driving your vehicle without
a trailer. This can help you avoid situations
that require heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. Because you’re a good
deal longer, you’ll need to go much farther beyond
the passed vehicle before you can return to
your lane.
Backing Up
Hold the bottom of the steering wheel with one
hand. Then, to move the trailer to the left,
just move that hand to the left. To move the trailer
to the right, move your hand to the right. Always
back up slowly and, if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns while
trailering could cause the trailer to come in
contact with the vehicle. Your vehicle could be
damaged. Avoid making very sharp turns
while trailering.
When you’re turning with a trailer, make wider
turns than normal. Do this so your trailer
won’t strike soft shoulders, curbs, road signs,
trees or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are still
working.
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Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary,
a lower gear selection if the transmission shifts too
often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode
if the transmission shifts too often. See “Tow/Haul
Mode” earlier.
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) for a few minutes before turning the
engine off. If you do get the overheat warning,
seeEngine Overheating on page 418.
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.
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 shift into PARK (P).
5. 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. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid (don’t overll),
engine oil, axle lubricant, belts, 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.
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Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with a trailer towing
harness. This harness with a seven-pin universal
heavy-duty trailer connector is attached to a
bracket on the hitch platform.
The trailer towing harness contains the following
trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Light Blue: Center High-Mounted Stoplamp
(CHMSL)
Red: Battery Feed
Dark Blue: Trailer Brake
A jumper harness for an electric trailer brake
controller and a trailer battery feed fuse may be
included with this trailering package. See
“Instrument Panel Jumper Wiring Harness” later in
this section.
If you need to tow a light-duty trailer with a
standard four-way, round pin connector, an
adapter may be included. See “Four-Wire Harness
Adapter” later in this section.
Instrument Panel Jumper Wiring Harness
Notice:If your vehicle has factory or
dealer-installed HUMMER off-road lamps, the
place where an electric trailer brake connection
must be made is already in use. Do not attempt
to double-up or “piggyback” the connection,
because this could cause a failure or damage to
your vehicle, the electric trailer brake system,
or both. If you want to connect a trailer with
electric brakes to your vehicle, see your dealer
to disconnect the off-road lamps. Also, read
Add-On Electrical Equipment on page 503for
more information.
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This harness may be included with your vehicle as
part of the heavy-duty trailer wiring package.
{CAUTION:
Be sure to use only the correct trailer
brake harness, the one intended for use
on your vehicle. If you use some other
trailer brake harness, even if it seems to
t, your trailer brakes may not work at all.
You could have a crash in which you or
others could be injured. Use only the
trailer brake harness intended for your
vehicle. If it is no longer available to you,
be sure to get a proper replacement from
your dealer.
This harness is for an electric brake controller and
includes a trailer battery feed fuse. It should be
installed by your dealer or a qualied service
center.
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