GMC 1996 Sierra Owner's Manual page 220

A
CAUTION:
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 Delco Freedom@
battery (or batteries) installed in every new GM
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,
explosive gas could be present.
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.
5.
Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some basic
positive (+) and negative (-) will go to negative (-)
or
a
metal engine part. Don't connect positive
(+)
to
negative
(-)
or you'll get a short that would damage
the battery and maybe other parts too.
1
things you should know. Positive
(+)
will go to
Fans or other moving engine parts can injure you
badly. Keep your hands away .from moving parts
once the engines are running.