GMC SIERRA 1997 Manual page 246

5. Connect the red positive
(+) cable to the positive
(+)
terminal of the vehicle with the dead battery. Use a
remote positive (+) terminal if the vehicle has one.
6. 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.