GMC Yukon XL 2015 Owner's Manual page 382

Caution
If any accessories are left on or
plugged in during the jump
starting procedure, they could be
damaged. The repairs would not
be covered by the vehicle
warranty. Whenever possible, turn
off or unplug all accessories on
either vehicle when jump starting.
4. Turn off the ignition on both
vehicles. Unplug unnecessary
accessories plugged into the
accessory power outlets. Turn
off the radio and all the lamps
that are not needed. This will
avoid sparks and help save both
batteries. And it could save the
radio!
5. Open the hood on the other
vehicle and locate the
positive (+) and negative ( )
terminal locations on that
vehicle.
The positive (+) terminal is under
a red plastic cover at the positive
battery post. To uncover the
positive (+) terminal, open the
red plastic cover.
For more information on the
location of the remote
positive (+) and remote negative
( ) terminals, see Engine
Compartment Overview on
page 10-5.
Warning
An electric fan can start up even
when the engine is not running
and can injure you. Keep hands,
clothing and tools away from any
underhood electric fan.
Vehicle Care
Warning
Using a match near a battery can
cause battery gas to explode.
People have been hurt doing this,
and some have been blinded.
Use a flashlight if you need more
light.
Battery fluid contains acid that
can burn you. Do not get it on
you. If you accidentally get it in
your eyes or on your skin, flush
the place with water and get
medical help immediately.
Warning
Fans or other moving engine
parts can injure you badly. Keep
your hands away from moving
parts once the engine is running.
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