S1 R33 Rb25det In S13 Wiring - Help Id 2 Lower Harness Plugs

[ANVIL]

Longshot but any wiring gurus help me out.... this harness was fully functional before pulled with the exception of my reverse lights not working. Just ugly and open exposed wires

Confused on a couple things

This plug. Has 2 thick wires one white and the other black. Both go to eyelet style ends. Pretty sure one for starter the other for alternator.... which is which?

This plug. Has 4 wires coming from it. Main colors being red, black, brown and yellowish. Idk if i damaged or cut when i removed it but the red, black and brown wires dont go to anything currently and the yellow one goes thru the harness to another plug that has 2 wires, the other being black

If anyone have any idea to why my reverse lights never worked please lmk what i can check to eliminate this harness as a possibility.

Kinda where i am right now. Need these then i can reloom everything.

[ANVIL]

First plug i believe i figured out. Both wires go to alternator.

2nd plug still clueless, beginning to think its extra and i dont need it. But i still want to know why its there and what it is supposed to be for. Looking at the s13 lower harness layout im guessing the 4 wires should go to exhaust gas temp sensor and the power steering oil pressure switch? Both of which i dont have connections for on this harness and i dont think are used on rb

Any input?

Edited February 2, 2016 by ANVIL