E36 engine harness with M20 plug and some issues.

[e30this]

ok I had a friend put a M20 engine harness plug on the end of my E36 engine wiring harness to clean things up so I didnt have to run and adapter and it be all bulky, etc.
We put labels on all of the plugs to make sure every plug had a place to go.
We had one plug that we didnt know where it went.
If I remember right it was a lime green and bright blue wire. I could be wrong. but the wire is as long as the o2 plug.

Does anyone know what this goes too?

Now since Im running the e36 harness and not the e34 harness I noticed there isnt a plug for the sensor thats in the bottom of the oil pan.
I dont have to worry about that since there isnt one on the e36 right?

but now onto my last question.
When the key is in the ignition and the car is started or the car is off and the key is out of the ignition the oil light in the top right corner of the check panel has a real light flicker to it.
Its always on and kinda blinking no matter what.
Does anyone know why this is or what it could be caused by?
Im sure it has something to do with the wiring harness but I dont know.

Any help would be perfecto.
Thanks fellas.

[e30serg]

Isn't the sensor at the bottom of the pan used for the oil level? The light you're seeing on you check panel also related to that.

[e30this]

hmm, maybe. But I dont have a plug in my harness for then and when I checked real oem there was just a cover plate for the e36 pan