Optimus 120-2117 - Manual (Page 3)

CAUTION: Be careful to avoid obstructions behind the mounting surface.
Routing Speaker Wire
If you install speakers, avoid routing the speaker wires near moving parts
or sharp edges. You can usually route them along the wiring channel
beneath the vehicle's door facing by carefully removing the molding that
holds the carpet in place. After you route the speaker wires, replace the
molding.
Testing the Stereo
Before you mount the stereo or any speaker, test the stereo by temporarily
connecting the power wire, speakers, and antenna as described in "Making
the Connections," below. If you plan to use an adapter harness to connect
the stereo, see "Using an Adapter Harness," below.
Making The Connections
The supplied harness with the 14-pin connector includes all the lead wires
you need to connect the stereo to ground, power, optional components, and
speakers.
IMPORTANT: Do not cut these wires. If you cut any wire, you cannot obtain
a refund or exchange on this product. However, your local Radio
Shack store will provide warranty service if you cut a wire and
find the product is defective.
Depending on your individual auto sound system, you might need additional
wire to complete connections. Your local RadioShack store carries a full
line of wire and wire management accessories.
CAUTIONS: For added safety and to protect your stereo, remember to
disconnect the cable from your vehicle battery's negative (-)
terminal before you begin making the connections.
You must connect the ground and primary wires first, then make
all other connections before you plug the 14-wire harness into
the stereo. (See "Using an Adapter Harness," below.) If you do
not make connections in the order shown, damage to the stereo
is possible if any wire connections are made incorrectly.
You must connect a separate wire to each speaker terminal as
described in the following procedure. Do not use a common wire
or chassis ground for any speaker connection.