Chevrolet 2002 Impala Owner's Manual page 258

To uncover the remote positive (+) terminal, lift the
plastic cap. You should always use the remote
positive (+) terminal instead of the positive (+)
terminal on the battery.
CAUTION:
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.
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