Constant 12V+ Blue/Yellow
Switched 12V+ Gray
Ground Brown (or your own wire to a metal grounding point)
Antenna Trigger Black/Red
Front Speakers 4" Dash
Left Front (+) Pink
Left Front (-) Purple
Right Front (+) Green
Right Front (-) Blue
Rear Speakers 5 1/4" Rear Deck
Left Rear (+) Black
Left Rear (-) Yellow
Right Rear (+) Red
Right Rear (-) White
I a '83 camry, there are 2 seperate plugs that go into a factory radio.
One for Power/and front speakers, and the other for rear speakers.
Sounds as if you are missing part of the harness for the rear speakers (or it is shoved in the back of the dash unused by the previous install). If there is not an un-cut plug in the dash - your only course of action would be to run your own set of speaker wire to the rear.
See this picture... these are the plugs that should go into your factory radio....
Metra kit 71-1938 will go from your factory wiring directly into your factory radio.
Thanks for using FixYa - a FixYa rating is appreciated for my effort in answering this Freebie question.