GMC 2008 Envoy Denali Owner's Manual page 339

4.2L L6 Engine
The remote negative ( ) terminal is located on
the front engine lift bracket for the 4.2L L6 engine,
and on the accessory drive bracket for the
5.3L V8 engine.
5.3L V8 Engine
9. Connect the other end of the negative ( ) cable to
the remote negative ( ) terminal on the vehicle with
the dead battery.
10. Now start the vehicle with the good battery and run
the engine for a while.
11. 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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