GMC 2003 GMT560 T-Series Owner's Manual page 196

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 things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if
the vehicle has one. Negative (−) will go to a heavy,
unpainted metal engine part or to a remote
negative (−) terminal if the vehicle has one.
Don't connect the positive (+) to negative (−) or
you'll get a short that would damage the battery and
maybe other parts too. And don't connect the
negative (−) cable to the negative (−) terminal on
the dead battery because this can cause sparks.
5-40
6. Connect the red
positive (+) cable to the
positive (+) terminal of
the dead battery. Use a
remote positive (+)
terminal if the vehicle
has one.
7. Don't let the other end
touch metal. Connect it
to the positive (+)
terminal of the good
battery. Use a remote
positive (+) terminal
if the vehicle has one.
8. Now connect the black
negative (−) cable to
the negative (−)
terminal of the good
battery. Use a remote
negative (−) terminal
if the vehicle has one.