What do these wires do.

[Lil-Pony]

Been trying to figure out what each wire in these pigtails do? I've been looking in my chiton and on the forms diagrams and I've been having trouble figuring this out.

 

[Lil-Pony]

By the way the wires are from a 84 b2

 

[adsm08]

The square grey one hooks the dash into the body harness. Things like rear lights and such. That yellow and white wire at the top left corner in the second pic is for the fuel gauge.

I'm not sure about the black plug. My 88 has it too, but I never really paid much attention to what it was for. It actually has two plugs like that, one I know is for the alternator, but I think those have different wire colors.

 

[Lil-Pony]

Well I cut both pigtails of the ECM harness.