GMC 2003 GMT560 T-Series Owner's Manual page 195

Squeeze the tab and open the case to access the
remote positive (+) terminal.
You will not see the battery (or batteries) of your
vehicle under the hood. They are located in
the battery box on the passenger's side of the
vehicle.
You will not need to access your battery (or
batteries) for jump starting. The remote positive (+)
terminal is for that purpose.
Open the hood of your
vehicle and find the remote
positive (+) terminal,
located under a red plastic
cover on the passenger's
side of the vehicle.
{
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 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,
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.
{
CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
®
5-39