GMC 2007 Sierra 1500 Pickup Owner's Manual page 526

Notice: If the jumper cables are connected or
removed in the wrong order, electrical shorting
may occur and damage the vehicle. The repairs
would not be covered by your warranty. Always
connect and 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
526
To disconnect the jumper cables from both
vehicles do the following:
1. Disconnect the black negative ( ) cable from
the vehicle that had the bad 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,
if your vehicle has one, to its original position.