Optimus 120-2152 - Manual (Page 8)

Note:
The labels on the wiring harness are for a two-pair connection. For a
one-pair connection, the labels are not correct.
1. Connect the grey 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 Two Pairs of Speakers
If you are using both front and rear speakers, follow these steps to
connect the harness with the 14-pin connector to the speakers.
1. Connect the grey wire to the right front speaker's positive
terminal. This terminal is usually marked with a plus (+) sign or
red mark.
2. Connect the grey/black wire to the right front 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 front speaker's positive
terminal.
4. Connect the white/black wire to the left front speaker's negative
terminal.
5. Connect the violet wire to the right rear speaker's positive
terminal.
6. Connect the violet/black wire to the right rear speaker's negative
terminal.
7. Connect the green wire to the left rear speaker's positive
terminal.
8. Connect the green/black wire to the left rear speaker's negative
terminal.