I have a plug that i think is the one i need to finish the cordia wiring. have no clue what it is though. It has 4 wires

black/yellow
black/white
black/red
yellow/green

It is a 91-94 harness.
any ideas? If i am right i think it connects to the chassis harness. It is located right by the ecu in the engine harness. also with it are two other plugs but i dont think i need them. Any help would be awesome. What does each wire go to if you can. Thanks.