Optimus 120-2117 - Manual (Page 5)

This wire does not provide power to the component. It simply turns
other equipment on or off. If you do not use this wire, secure it
with a wire tie and do not let it touch metal.
Connecting Speakers
1. Connect the gray wire to the right speaker's positive terminal. This
terminal is usually marked with a plus (+) sign or red mark.
2. Connect the gray/black wire to the right speaker's negative terminal.
This terminal might be marked with a minus (-) sign or it might not be
marked at all.
3. Connect the white wire to the left speaker's positive terminal.
4. Connect the white/black wire to the left speaker's negative terminal.
Connecting the Antenna
Connect the vehicle's antenna cable to the stereo's antenna jack at the
back of the stereo.
Completing the Connections
After you have securely made all other connections, plug the l4-pin
connector into the stereo's 14-pin wiring socket.
Then reconnect the cable to the vehicle's negative (-) battery terminal.
Testing The Connections
Turn on your vehicle's ignition, install the stereo's faceplate and test
the stereo.
If the stereo does not work, immediately disconnect your vehicle battery's
negative (-) terminal. Then recheck your connections.
After you test the stereo and verify that everything works, make sure the
connections are marked or identified. Then follow the instructions in
"Mounting the Stereo," below.
Mounting The Stereo
Be sure you test the stereo first and verify that it works properly.