GMC 2003 Sonoma Owner's Manual page 311

2. Get the vehicles close enough
so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure
the transfer case is not in NEUTRAL (N).
Notice: If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all lamps that aren't needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
4. Open the hoods and locate the batteries. Find the
positive (+) and negative (-) terminal locations on
each vehicle. See Engine Compartment Overview
on
page
5-12 for more information on location of the
battery.
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.
Be sure the batteries have enough water. You
don't need to add water to the ACDelco@
battery (or batteries) installed in your new
vehicle. But if a battery has filler caps, be sure
the right amount of fluid is there. If it is low,
add water to take care of that first. If you don't,
Battery fluid contains acid that can burn you.
Don't 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.
~
explosive gas could be present.
5-48