GMC Yukon 2007 Owner's Manual page 496

The remote negative (-) terminal is a stud located
on the right front of the engine, where the
negative battery cable attaches.
See Engine Compartment Overview on page 462
for more information on the location of the
remote positive (+) and remote negative (-)
terminals.
496
CAUTION:
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An electric fan can start up even when the
engine is not running and can injure you.
Keep hands, clothing and tools away from
any underhood electric fan.