wire harness confusion and questions

[Tippey764]

Hey guys I've been reading a lot about the wiring for an s52 swap in an e30 but I'm having some misunderstanding with some things and can't seem to find any info on it

1: There are 3 connectors on my engine harness, x20 x69 and x6031. Everyone talks only about the x20 conenctor but what do I do with the wires in the x69 and x6031? Theres only a 4-5 wires in one of them and another 6-8 in the other one.

2: The engine coolant temperature sensor, I have the correct brown top coolant temperature sensor but where do you plug this in at? I have it installed where the coolant lines to the throttle body go but obviously there was never a connector nearby for it. Do I need to run an individual wire from this to the c101?

3: Where can I get a grommet for the ECU connector as it travels inside of the car?

4: check engine light, how do I wire this up so it works? My car is an 88 m3 and never came with a check engine light from the factory of course. '

5: oil temperature gauge, anyone have any info on how this is to be wired up to an s52?

[Tippey764]

bump?

[Klug]

Man, I need an answer to #1! Ugh- do I cut this x6031 out or what!?

(free bump)

[ba114]

1. keep the x6031
2. Cut the brown wire with violet stripe from your 4 pole coolant sensor in the head. Cut the coolant temp sensor wiring from your e30 engine harness and wire it to this.
3. Cut it off your e30 harness
4. CEL comes from pin 20 on the 24v DME. Wire a new light to a spare hole in the back of your cluster. One wire goes to switched 12v, the other goes to pin 20 dme. The dme grounds this pin when CEL is active.
5. No idea

[7pilot]

5, buy an adapter to tap into the oiling circuit.
it installs where the oil pressure switch is on your engine.
screw in the factory oil temp sender, then add some wire and connect it to C101 T19.

If you retain the s14 instrument panel, tho, you may have to insert a coding plug from an M20 instrument panel for the Tacho.

m

[Klug]

circling back as I figured it out- I kept the x6031 as stated. It'll provide the c101 the CEL light in addition to some other useful leads for ODB2 (like hard wiring an ODB2 port in the cabin)