Buick 2004 Century Owner's Manual page 260

Notice: If the jumper cables are removed in the
wrong order, electrical shorting may occur and
damage the vehicle. The repairs would not be
covered by your warranty. Remove the jumper
cables in the correct order, making sure that the
cables do not touch each other or other metal.
Jumper Cable Removal
A. Heavy, Unpainted Metal Engine Part or Remote
Negative ( ) Terminal
B. Good Battery or Remote Positive (+) and Remote
Negative ( ) Terminals
C. Dead Battery or Remote Positive (+) Terminal
5-48
To disconnect the jumper cables from both vehicles do
the following:
1. Disconnect the black negative ( ) cable from the
vehicle that had the dead battery.
2. Disconnect the black negative ( ) cable from the
vehicle with the good battery.
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the other
vehicle.
5. Return the remote positive (+) terminal cover to its
original position.