1985 325e to 1989 325i wiring

[kamotors]

car setup
1985 bottom end
89 325i top end
89 325i toothed crank pulley
89 325i cooling system
Megasquirt ECU

SO I've been building a 327i turbo for a friend and the wiring harness that was with the 325i head is unusable and damaged, at least 4 wires are broken, and the rest have the insulation cracked and broken off leaving exposed wiring.

Since this car is an 85 the Fuse box connector is a square plug instead of the round late model plug.

I read online that a 1987 325i wiring harness is plug and play because it uses the square connector as well but I cant seem to fin any images/ or local 87 325i's to confirm that. Is this true?

What harness will be best to use? should I make a adapter to connect the fuse box from square to round or should I look for the 87 harness?

also will the OEM dual pump setup even work with the 325i harness?

[jlevie]

The 87 M20B25 wiring harness has a round C101, so it isn't plug-n-play. The best solution is to get the body side of a round C101 and replace the square part in the car now. If the harness needs to be changed later no mods will be needed.

The fuel pump set up will work with the M20B25 harness.

[KEVORM]

http://www.e30tech.com/forum/showthread.php?t=28921

This has everything you need. Just follow the directions and connect like number to like number.

I had a body side round and an engine side square that i wired together to make into a "adapter" of sorts.



I used a 89 engine harness for my i motor so i had to splice into the c104 to get tach, that is also described in the link above.

87 is plug in play in that you dont need to splice, all you need is to make square meet round.

[Dr. Anthony]

Sorry for reviving an old thread, but since e30tech is down, is there ANY where else you know where to get this info from?
That plug you have is the exact plug I need.

I've been searching for a few days and stumbled on your thread.


I'm in the middle of doing a 325i swap from an 86 into my 84 325e (11/83 build)

http://www.e30tech.com/forum/showthread.php?t=28921

This has everything you need. Just follow the directions and connect like number to like number.

I had a body side round and an engine side square that i wired together to make into a "adapter" of sorts.



I used a 89 engine harness for my i motor so i had to splice into the c104 to get tach, that is also described in the link above.

87 is plug in play in that you dont need to splice, all you need is to make square meet round.

[Klug]

Sorry for reviving an old thread, but since e30tech is down, is there ANY where else you know where to get this info from?
That plug you have is the exact plug I need.

I've been searching for a few days and stumbled on your thread.


I'm in the middle of doing a 325i swap from an 86 into my 84 325e (11/83 build)

See if it is on this Google Drive of e30tech screenshots. Kudos to the original owner of this folder!

https://drive.google.com/open?id=0B-PuO9ReYNk0cDVsU2tWOTJNY1U

[Dr. Anthony]

See if it is on this Google Drive of e30tech screenshots. Kudos to the original owner of this folder!

https://drive.google.com/open?id=0B-...DVsU2tWOTJNY1U

Thank you! I will take a look

[sweet3]

If you decide that you rather just get an adapter, I can help you out. I make the c104 and square c101 connectors. So you no longer have to send them to me to have one made.

[Dr. Anthony]

If you decide that you rather just get an adapter, I can help you out. I make the c104 and square c101 connectors. So you no longer have to send them to me to have one made.

I haven't had time to play with it since I made this thread. How much do you sell the adapters for?

[Jphillips14]

If you decide that you rather just get an adapter, I can help you out. I make the c104 and square c101 connectors. So you no longer have to send them to me to have one made.

I really wish this guy was still around lol

[paynemw]

Let me clarify a few things for you. Not ALL 1987 325i harnesses are Motronic 1.3. Early production 87 325i cars were M1.1 which does not have the C191 connection at the fuel injectors. So I think mid year 87 they started putting in M1.3 which has the C191 plug at the fuel rail. You can tell by looking at the fuel rail and if there's a fuel rail and then another rail that holds the harness then it's a M1.3 Also, the M1.3 cars had the 63L fuel tank. Those fuel tanks are set up differently and don't have the primer pump in the tank like early production 87 and previous cars. So unless you plan on converting to a larger gas tank AND your can source a M1.3 harness, you need to find an 86 or early production 87 harness. HOWEVER, they aren't the easiest to find. You can also possibly snag a vert - however their engine harness is different slightly because they have the battery up front. I'm sure you can easily convert a "vert" harness to a coupe/sedan harness, but I've never done it. from what I've read, the only thing you really don't want to "repair" as far as harnesses on these cars are associated with ABS, I can't think of anything sans the CPS sensor that requires so much sensitivity WRT resistance. PS... make sure the crank bearings are new and put a baffle in there, or he'll be doing what I did... read the thread, it aint cheap.