GMC Sierra 2015 Owner's Manual page 460

9. Connect the black negative ( )
cable to the negative ( ) terminal
of the good battery. Use a
remote negative ( ) terminal if
the vehicle has one.
Do not let the other end touch
anything until the next step.
10. Connect the other end of the
negative ( ) cable.
4.3L Shown, 5.3L and 6.2L Similar
To the metal bracket that is
bolted to the engine and
supports the resonator, on
the vehicle with the dead
battery.
6.0L
To the generator bracket, on
the vehicle with the dead
battery.
Vehicle Care
6.6L
To the negative ( ) post on
the auxiliary battery, on the
vehicle with the dead battery.
11. Start the vehicle with the good
battery and run the engine for a
while.
12. Try to start the vehicle that had
the dead battery. If it will not
start after a few tries, it
probably needs service.
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