Can't find my C104

[Kerrath]

I'm slowly working out a bunch of finalizing details on my M50 swap.
I went to start wiring up my tach wire and the others from the C104, I couldn't find it.
I found the old ICV control unit up in the box and a couple other random wires, but no 3-pin connectors and no other connectors with any of the right colors.

I've searched for a long time and can't find specific details or picture that would clearly illustrate where to look.

After finding out my headers won't let my O2 sensor fit without bending the pipes or cutting the firewall found out I couldn't find the C104, really damn annoying.

If you can help me out, I'd really appreciate it.

Edit: Forgot to mention what my car is;
1986 325e with N/V M50B25

[smonkbmw]

early models dont have c101 connectors IIRC. what headers?

[Kerrath]

Isn't C101 the connector that goes to the engine?
C104 is the one I'm looking for. Supposedly it's in the glove box and is 3 pins, I saw no such thing.

I got the eBay stainless headers that are the most common kind available. they're all the same pretty much, just different sellers. There are two spots for O2 sensors, one in the 1-3 header and the 4-6 header. The 1-3 header is close to the 4-6 header and the O2 sensor wouldn't fit unless it were forcibly separated and it just springs back. The 4-6 header locates the O2 sensor like an inch into the foam on the firewall.

I know up to 85 used a square C101 and 86+ theoretically uses a round one. That's what I've read. But I have the engine harness done enough that the engine runs. I need to get some functions working though, coolant and tach and the speed sensor that's supposedly necessary to be added to the ECU.

[tonytony]

are you planning on a custom exhaust? If so you can just have them weld in a o2 bung on the new pipe after the headers. You'll have to get a new o2 sensor with longer wires, i dont have the part number for it but bav auto sells them. YOu can check their site and get the o2 part number and get it at your local autoparts store.

[Mot]

you wanna order a e34 525i auto o2 for the longer cable on the o2. It's what I'm running on my obd1 m52 and its plenty long to get back to where my o2 bung is post headers.

[smonkbmw]

yeah what Mot said. are you not using e36 midpipes? if so youd use the stock location before the cats. and cap off the o2 bungs on the headers. i ran obd2 manifolds and thats how i ran it.

Isn't C101 the connector that goes to the engine?

yes it is, didnt mean to insult your intelligence, didnt know if there was a mix up here with the terms or not.

[tonytony]

what about what tony said:( I said what mot said just more complicated haha

[Kerrath]

Aha, here's a problem:

Already had the exhaust made. I had to get it out of one driveway and to another by a deadline and I didn't want to pay out the ass for towing expenses.

I've thought about asking the shop to add a bung when I go to get my resonator added (not in stock when I went) and I'm gonna call him today to ask how much he thinks it'd cost.

Exhaust is so much cooler than C104's but that's what I need the help with.;)

[rs4pro3]

It's a white 3-pin flat plug, look by the radio etc.. it runs from the driver's side of the dash over so it could of been pulled over that way by accident.

[Kerrath]

Thanks, thats a good place to start. And the wires should be black, green and white? I just want to make sure now. Where my car is, there is no internet. Makes for a huge pita.

[rs4pro3]

yes the third wire may be yellow with a white stripe, as it changes colors at the plug.

[Kerrath]

I just had a thought. I don't know where it connects to, but I assume it's behind the cluster, so would it be easier to follow it to the end that's supposed to be in the glove box from there?
Makes sense to start with a known rather than a should-be.