GMC 2001 C3 Owner's Manual page 243

Instrument Panel Jumper Wiring Harness
This harness is included with the heavy
-
camper/fifth wheel trailer wiring packages. The harness
is for an electric trailer brake controller and includes a
trailer battery feed fuse. This harness and fuse should be
installed by your dealer or a qualified service center.
4-58
Step-Bumper Pad
Your vehicle is equipped with rear step pad in the center
of the bumper.
-
duty and
If you will be using the
bumper to tow a trailer,
you must remove the
center cutout circle to
install the trailer ball.