Optimus 120-2154 - Manual (Page 9)

(White) - Left Speaker (+)
(White/Black) - Left Speaker (-)
(Gray) - Right Speaker (+)
(Gray/Black) - Right Speaker (-)
(Green) - |\
(Green/Black) - |\\___ Do Not Connect
(Violet) - |//
(Violet/Black) - |/
For 12-2154: If you are using only one pair of speakers, remove the tape
that holds the mounting sleeve in place and slide the sleeve
off of the stereo. Then set 2CH/4CH on the bottom of the
stereo to 2CH. Then follow these steps to connect the
harness with the 14-pin connector to the speakers.
(This section has been corrected. See Faxback Doc. # 48535.)
(White) - Left Speaker (+)
(Green) - Left Speaker (-)
(Gray) - Right Speaker (+)
(Violet) - Right Speaker (-)
(White/Black) - |\
(Green/Black) - |\\___ Do Not Connect
(Gray/Black) - |//
(Violet/Black) - |/
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 violet 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 green wire to the left speaker's negative terminal.
Connecting the Antenna
Connect the vehicle's antenna cable to the antenna jack on the back of the
stereo.
Completing the Connections