2005 GMC YUKON wiring

The rear doors of your vehicle cannot be opened from
the inside when this feature is in use. If you want to
open the rear door while the security lock is engaged,
unlock the door and open the door from the outside.
Lockout Protection
This feature protects you from locking your key in the
vehicle when the key is in the ignition and a door
is open.
If the power lock switch is pressed when a door is open
and the key is in the ignition, all of the doors will lock
and then the driver’s door will unlock.
Liftgate
{CAUTION:
It can be dangerous to drive with the liftgate
glass, liftgate or rear doors open because
carbon monoxide (CO) gas can come into your
vehicle. You cannot see or smell CO. It can
cause unconsciousness and even death.
If you must drive with the liftgate glass,
liftgate, or rear doors open, or if electrical
wiring or other cable connections must pass
through the seal between the body and the
liftgate glass, liftgate, or rear doors:
Make sure all other windows are shut.
Turn the fan on your heating or cooling
system to its highest speed with the
setting on VENT or OUTSIDE AIR. That will
force outside air into your vehicle. See
Climate Control System on page 3-21.
If you have air outlets on or under the
instrument panel, open them all the way.
SeeEngine Exhaust on page 2-39.
2-13

A circuit breaker protects your headlamps. If you have
an electrical overload, your headlamps will icker on and
off. Have your headlamp wiring checked right away if
this happens.
Headlamps on Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on and your ignition
is off, in LOCK, ACCESSORY, or your door is open.
To disable the chime, turn the light off then back on.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. Fully functional
daytime running lamps are required on all vehicles
rst sold in Canada.The DRL system will come on when the following
conditions are met:
The ignition is on
The exterior lamps control is in AUTO
The automatic transmission is not in PARK (P)
The light sensor determines it is daytime
When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won’t be
on. The instrument panel won’t be lit up either.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
When you turn the headlamp switch off, the headlamps
will go off, and your DRL lamps will illuminate,
provided it is not dark outside.
Shifting the transmission into PARK (P) will allow you
to idle the vehicle with the DRL off. The DRL will stay
off until you shift the transmission out of PARK (P).
This procedure applies only to vehicles rst sold in the
United States.
3-15

Fog Lamps
If your vehicle has fog lamps, use them for better vision
in foggy or misty conditions.
The fog lamp button is
located on the left side of
the instrument panel.
Your parking lamps and/or low-beam headlamps must
be on for your fog lamps to work.
Press the button to turn the fog lamps on. Press the
button again to turn them off. An indicator light will glow
in the button when the fog lamps are on.
Remember, fog lamps alone will not give off as much
light as your headlamps. Never use your fog lamps
in the dark without turning on your headlamps.
The fog lamps will go off whenever your high-beam
headlamps come on. When the high beams go off, the
fog lamps will come on again.The fog lamps will be cancelled after the ignition is
turned off. If you still want to use the fog lamps after
you restart the vehicle, you will need to press the
fog lamp button again.
Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This button is located
on the center of the
instrument panel near
the climate controls.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the button will activate the
lamp and illuminate an indicator light near the button.
Pressing the button again will turn off the roof
mounted lamp.
3-17

Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
be provided for several seconds to remind people to
buckle their safety belts. The driver safety belt light will
also be provided and stay on for several seconds,
then it will ash for several more. You should buckle
your seat belt.
If your vehicle is not
equipped with the
passenger sensing system,
this chime and light will be
repeated if the driver
remains unbuckled and
the vehicle is in motion.
SeePassenger Sensing System on page 1-75for more
information.
If the driver’s belt is buckled, neither the chime nor the
light will come on.
Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensors, the airbag modules, the passenger sensing
system (if equipped), the wiring and the crash sensing
and diagnostic module. For more information on the
airbag system, seeAirbag System on page 1-66.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
This means the system
is ready.
If the airbag readiness light stays on after you start
the vehicle or comes on when you are driving,
your airbag system may not work properly.
Have your vehicle serviced right away.
3-39

Q:What is total vehicle reserve capacity?
A:This is the difference between your GVWR and the
weight of your vehicle with full fuel and passengers.
It is the amount of weight you can add to your
vehicle before reaching your GVWR. Keep in mind
that reserve capacity numbers are intended as
a guide when selecting the amount of equipment or
cargo your vehicle can carry. If you are unsure
of your vehicle’s front, rear, or total weight, go to a
weigh station and weigh your vehicle. Your
dealer can also help you with this.
The total vehicle reserve capacity for your vehicle
can be found in the lower right corner of the
Certication/Tire label as shown previously.
See your dealer for additional advice and information
about using a snow plow on your vehicle. Also,
seeLoading Your Vehicle on page 4-51.
Emergency Roof Lamp Provisions
Vehicles with the RPO VYU snow plow prep package
also have an emergency roof lamp provision package,
RPO TRW. Wiring for the emergency roof lamp is
provided in the B-pillar as shown. SeeAuxiliary Roof
Mounted Lamp on page 3-17for switch location.
A. Body Side Inner Panel
B. Emergency Roof Lamp Harness
4-61

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.
Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harnesses for towing a trailer.
4-78

Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to
the vehicle’s frame. The harness connector can be
plugged into a seven-pin universal heavy-duty trailer
connector available through your dealer.The seven-wire 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
Red: Battery Feed
Dark Blue: Trailer Brake
4-79

Heavy-Duty Trailer Wiring Harness
Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
trailer connector is attached to a bracket on the hitch
platform.
The seven-wire 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
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 and properly charge the battery.
Electric Brake Control Jumper
{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.
4-80