s54venture

I've got a 1982 928 Competition
I was messing around with the center console for different reasons, and took it upon my self to try to fix the wiring that someone in the past had messed with.
There were damaged wires and uninsulated splices, and since someone messed with it, the wire wrap was all gone so it was a bunch of loose wires.
I tidyed it up and wired everything back how it was, or clearly was supposed to be, and only two things I didn't know where they go.

I figured out that someone had disabled the seat belt warning light by just cutting the wires on the light itself.

When I supply pin 1 with ground and pin 2 with 12 volts it lights up.
Now what it looks like to me is that the white wire with a purple stripe is the power wire from the relay (pin 8), which is the only place it goes to, and it looks like the black wire with blue stripes is supposed to be the ground wire (it goes to relay pin 9 and then further into the harness).

The black wire with blue stripes gets a ground continuity when the ignition is off, just like every other black and blue wire I saw.
The problem I see is the black and blue wire was cut on the harness, and spliced to the solid brown wire going to the relay, then a brown and white wire came off the same pin on the relay and spliced back into the black and blue wire.
I put it back together like that because it seemed to me black and blue and browns were all grounds anyway.
The weird thing is, the blue wire gets 10volts with the ignition in the accessory position, but has continuity to ground when the ignition is off.

I've thought now that maybe it uses the ground off the OSX light connection and black and blue is for while the engine is off and the key is on, and white and purple is when the engine is on and the seat belt isn't latched, but with out having the right relay I can't test that.

I've made a few images showing the wiring.








And on a side note, I'm not sure where this plug goes,



It has continuity with ground, my guess is it is used for the stock windows switches.


Any help with any of this is appreciated.
Thanks!