Z3s and Z8s have these little modules that sit between the cruise controls stalk and the ECU.
The big connector connects to the cruise controls stalk. The little three-pin connector plugs to the ECU, via some connector, somewhere.
I will be using one of these to interface the E28 cruise stalk to my S54 ECU. Basically the pinout of the NON-M E36 Z3 and E52 Z8 cruise stalk is analog, just like the E28, but with a slightly different pinout. The Z3 M had (apparently) the same stalk as the E46 M3, so this adapter wasn't needed.
I need to modify the Z3 adapter such that it plugs into the E28 cruise control stalk pigtail per the pin layout described above. Easy.
According to the ETMs (plural, because between 83 and 85 the diagrams changed, but the wiring DID NOT) there should be a plug (C210) with four wires in it that plugs into the pigtail that comes from the cruise control stalk. Said wires should be VI/WT, YL, BU, GN.
On Minerva, which has a harness from a 1985 Euro 528i in it, that plug exists, as expected. It's glorious:
I could cut Minerva's C210 plug off and splice it onto the Z3 adapter. But I don't want to do that, because so far I've avoided doing anything to the harness that's not easily reversible (on principle, not because I actually think I'll EVER do it).
So, I looked on the 88 535is harness I had in my stash. The C210 plug you see above is nowhere to be found.
Yesterday I pulled the harness from the 85 US 533i parts car and THE PLUG IS NOT THERE EITHER.
@Ahab sent me a picture of his car, and the plug is there.
So strange things are afoot at the Circle-K and I'd like to understand. I could just plow ahead and cut Minvera's C210 plug off and use it, but DAMMIT I want to KNOW.
Why is that plug missing from the two spare harnesses I have?
