Early square c101 wiring for m50 swap

[Jackhdmn]

Hey everyone, I have a 85 325 (84 build date) that I would like to do a m50 swap in. My issue is that because my car is so early I have the square c101 and I can't to seem much information on wiring in the 24v wiring harness.

I have read that people change their square c101 to a round c101. Is changing to a round c101 necessary? If so how would I change it or would I have to change my wiring harness. If I didn't change the c101 could I just wire the square c101 to the x20 or is it not that simple?

If anyone has any good information on wiring in the 24v harness or a wiring digram for the square c101 it would be much appreciated.




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[GunMetalGrey]

Don't mean to be rude but man you should really use google or the search function here before posting. I have done this before but all you need to type in is e30 square c101 and this is the first thing that comes up

You do not HAVE to switch the body side to a circle plug, but you need matching connectors (obviously). I did a friends car and just put the square plug on the engine harness. You do need to run a couple of wires over to the glovebox from the engine harness for a couple of sensors. There is plenty of info about swapping it, just have to search.

[justin_l_]

I know I posted how to wire it too back when I did the orange car.

[Jackhdmn]

I've spent a lot of time on google but I never typed in anything that simple in. But thanks for the pic!


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[Jackhdmn]

I know I posted how to wire it too back when I did the orange car.

Where is this posted? I guess it also didn't come up in my google searches.


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[M3PO]

I put the round connector onto the body side of my 84. The body side has less wires to fuss with. Then you can just leave the engine harness alone. As mentioned, with the early cars, you will have to add a few wires.

I ran extra wires for:
-Tach
I traced the C104 wires back to the cluster and tapped into the tach wire (black) there, ran a wire to appropriate pin of the E36 harness

-Econoguage
Same as the tach but it's the yellow/white wire

-CEL
The DME uses a switched ground to illuminate the CEL. I mounted a little LED in the dash, provided it switched 12V power (from the stereo) to one pole, and ran a ground wire from the correct pin on the E36 harness to the other pole.

-VSS
I had to solder a wire to one of the three pins on the green connector on the back of the cluster and then ran that to the correct pin on the E36 harness.

-Oil Level Sensor
The oil level sensor has three wires: Static and dynamic levels and a ground. I grounded the brown wire to the E36 harness and ran two wires through the E36 harness, through the connector, to the correct E30 pins.

[justin_l_]

http://www.e30tech.com/forum/showthread.php?t=76315

Scroll down to the wiring section.

[Jackhdmn]

Thanks so much for the help!


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