Homemade e30 chassis to m50 harness adapter

[omar85]

Instead of buying an adapter I figure I would make my own but before diving into it, I want to make sure what I am doing can work. I got the motor side on a C101 from a 325is and the chassis side of an X20 from a 98 M3. I figure just look at AKG's diagram and solider the wires together that need to be connected.

If I can get help making it work I think many people here would stop making threads like this one. :) I didn't find much with the searches I did.

I got the diagram from here

http://www.akgmotorsport.com/swaps.html

and here are the parts that i have.



The diagram got distorted when i copy and pasted but it's in the link i provided.

From Pin #ForTo Pin # '86-91 325 '92+ 325i, M3 1Alternator charging25 2Oil level sensor 3Not used 4Coolant temperature sender12 5Oil pressure23 6Oxygen sensor, heater relay13 7Ignition switch21 8Not used 9Not used 10Oil level sensor 11Diagnostic connector19 12Check engine light control 13Fuel pump relay 14Oil level fault set 15Not used 16SRS connector/diagnostic connector #6 not used 17Not used 18Starter18 19Not used 20Not used C104 under glove boxEngine speed output, BK/BU Tach 20

[surebimmer]

search for "c101 and x20"

http://www.r3vlimited.com/board/showpost.php?p=550931&postcount=56

http://www.r3vlimited.com/board/showpost.php?p=542432&postcount=35

[omar85]

thanks i'll compare those to the one AKG has on his site.

do you think what i am doing should work ok. i don't see why not but I just wanted the opinion of someone who has done this before.

[416stroker]

It will work why wouldn't it. You just have to know what your doing.

And surebimmer has a 24v car

[pedal2metal]

I got an AKG adapter harness and had to add the wire that turns on the check engine light. Only one wire, no big deal, I can't remember which pins so check the bentley.

[hoveringuy]

I wouldn't even mess with an adapter. Just wire the C101 onto your DOHC harness.

Were you planning on putting the motor back into an e36 chassis?

[omar85]

p.s. my car is a 91 318i. i am just assuming that the body harness is the same????

I wouldn't even mess with an adapter. Just wire the C101 onto your DOHC harness.

Were you planning on putting the motor back into an e36 chassis?

i was thinking about that but i would rather just do this encase i make a mistake, i dont want to work in my engine bay. i would rather just unplug it and modify it.

[omar85]

surebimmer:

http://www.r3vlimited.com/board/showpost.php?p=542432&postcount=35

8-24 fuel rate
9-14 Tach

no wires exist here on the c101 and the AKG diagram says not used?

[derrith]

Okay, I'm coming at this having used the vast amount of information available here to swap an m50b25 into my e28. When I went to make an adapter I did as others suggested, tracked down the ETM for both the donor (a 1992 325i in this case) and my 1985 528e. The e30 bodyside c101 pinout changed significantly across model years, you need to get the ETM for your year and do the hard work of searching for all the connections. There's no way you're going to get an accurate and correct setup unless someone did the swap with your exact car and engine and you're willing to completely trust someone else on the internet with your car.

[omar85]

i agree, especially because my car is 318, not a 325i/is, and the c101 i am using it from an 87 so it doesn't even have 3 of the pins in the diagram in the link posted. i just want as much info as possible as a place to start.

[MattM]

i made an adapter originally, pretty easy, then it ended up being the big clucky thing that i couldnt make look nice or tuck out of the way, i ended up cutting it out and splicing the C101 directly to the engines wiring harness like hoveringuy said... looks way cleaner, mine is a PFL car, so the square plug mounts along side the fuse box, so i have only one connection that anyone can see, and thats the diag port, that is in the spot that the x20 would be on the M42 plasic wiring trim... looks very tidy

[416stroker]

surebimmer:

http://www.r3vlimited.com/board/showpost.php?p=542432&postcount=35

8-24 fuel rate

9-14 Tach



no wires exist here on the c101 and the AKG diagram says not used?

Thats because they are not all the same akg is wrong there. Get the ETM for your car

i agree, especially because my car is 318, not a 325i/is, and the c101 i am using it from an 87 so it doesn't even have 3 of the pins in the diagram in the link posted. i just want as much info as possible as a place to start.

thats a problem right there cut your old m20 harness. early models have differnt pin-outs than lates. I just cut my x20 off also and spliced it to me c101 also.

[kevmo707]

would the adapter be different for an 89 325is compared to a 318is?

[Fidhle007]

Yes.

[kevmo707]

how???? i got my adapter from mazur and i think he has a 318is and putting an s52 in an 89 325is