OBC temperature sensor; wiring mystery

[Thud]

Okay, so I finally got a chance to install the OBC temperature sensor I've been holding for the past few months, into my 1990 325i convertible.

I already had the sensor unit and two plugged-in leads coming off it that connect to the leads from the OBC. I posted a few months back asking whether polarity was an issue, since the two leads that come of the sensor unit are both black with no markings. I concluded from the responses I got that it was not an issue.

Now here's my new dilemma:
I originally thought that the two stray black leads hanging together behind the driver side headlight were meant for the temp sensor, and that I'd splice and connect them to the two black leads plugged into the sensor and that would be that. But when I peeled back the black insulation on one of the "leads" hanging behind the lights, I found that it contained (not one but) two leads, one brown wire and one green wire (it could be blue since exposure seems to have altered the color); the other black "lead" contained a red (or red w/white stripe) lead. I'll have to go back in and cut away more of the black insulation to find out the actual colors of the leads next weekend.

In the meantime, I'm wondering if anyone can tell me if these are even the right leads for the sensor, or if they're meant for something else. I have Chilton's, Haynes', and Bentley's, and only Bentley's seems to have a wiring diagram that includes OBC wiring; it shows that a brown wire should come in to the sensor and a blue should come off the sensor.

If these (or any of these) are the right wires, how should the unit be hooked up? If the green wire is actually blue, then that part of the mystery is solved, but it's the red one that's really throwing me. I've got three leads coming off the car and only two coming off the sensor, and I'm a little perplexed.

Any ideas?