Engine wiring harness question

[JoeMadoo]

It's not that bad man, totally worth it.

[Jean]

Ok so here is the harness I got and the PO isn't 100% sure exactly what chassis/year it came out of other than "it's from a M30B35 that was put into an E28 by a friend of mine. The car was a 5-speed"

Can someone identify it if it's an e28,e32, or e34 harness?

[BenM]

Definitely not an E28 harness. Definitely an E32 or E32, but I can't tell.




That round connector is the fusebox plug, which you will need to splice into your 318i fusebox (C101), or hack up your 318i harness and use the fusebox plug from that. Of course you'd have to figure out the pinouts from both your 318i and newly acquired B35 harness and splice them.

Someone may want to chime in if this is a bad idea. HTH.

[Jean]

Thanks! I am going to pick up a rectangular c101 and round c101 plugs from parts cars and make an adapter as I don't want to cut the chassis or the engine harness...

[E30SPDFRK]

90% sure that is a e34 harness.

Cut off this plug


and splice the plug from the engine side of the 318 harness onto it.
Edit: just saw you are making an adaptor, disregard this then.



There are only 11 or so wires that you need from that harness, the rest are for systems the e34 has that the e30 wont. I have the pinouts of the wires you need from that harness, but I don't know where I put them. I'll post them up when I find them.

[euroshark]

I'm 99% sure that's an E32 harness. The batteries are mounted under the rear seat in an E32, so those wires that are near the relays that come through the same big grommet that the ECU connector comes through, and all of that stuff is on the passenger side of the engine compartment in a sealed box. All of the power wires connect to the power distribution block just like an E30 with a trunk mounted battery.

[Doughnut]

That round plug has a blue wire in it that goes to your alternator excite use the one that has already been spliced. (for battery light on the dash and to charge the battery)



The thick yellow wire in this photo is not original just so you know, those red wires go to 12v+




The two terminals go to the coil (green positive, brown negative) the wire off to the bottom right is earth for the engine harness put it to ground (not the coil negative)



You can't get these plugs around the wrong way just so you know, one is for your cps must be pluged in for engine to start.

Yep, cut this female round plug off and your square engine harness plug off the old engine and solder the wires for direct plug into the chassis harness.

If you already knew this stuff just disregard this post. Good luck, PM me for more detailed stuff that you get caught on as I was in the same position as you.

Just use the motronic 1.3 m30 harness, and not your original jetronic 84' harness will not work with this engine.

Joseph.

[Jean]

That round plug has a blue wire in it that goes to your alternator excite use the one that has already been spliced. (for battery light on the dash and to charge the battery)

Q" What is the black with a spade above for?



The thick yellow wire in this photo is not original just so you know, those red wires go to 12v+




The two terminals go to the coil (green positive, brown negative) the wire off to the bottom right is earth for the engine harness put it to ground (not the coil negative)

Q: two go to the ignition coil and the other 2 are ground yes?



You can't get these plugs around the wrong way just so you know, one is for your cps must be pluged in for engine to start.

Q: one is CPS, and what is the one right next to it for?


Yep, cut this female round plug off and your square engine harness plug off the old engine and solder the wires for direct plug into the chassis harness.

That's what I am about to do, got the extra rectangular c101 plug today to connect to the fuse box.

If you already knew this stuff just disregard this post. Good luck, PM me for more detailed stuff that you get caught on as I was in the same position as you.

Just use the motronic 1.3 m30 harness, and not your original jetronic 84' harness will not work with this engine.

Joseph.

[Jean]

I'm 99% sure that's an E32 harness. The batteries are mounted under the rear seat in an E32, so those wires that are near the relays that come through the same big grommet that the ECU connector comes through, and all of that stuff is on the passenger side of the engine compartment in a sealed box. All of the power wires connect to the power distribution block just like an E30 with a trunk mounted battery.

Thanks, I looked at a 735i today and the harness looks the same as mine, other than the car being auto and this harness is from a 5speed car.

[Doughnut]

Q" What is the black with a spade above for?

Not sure.

Q: two go to the ignition coil and the other 2 are ground yes?

the one with the blue crimp connector is brown/orange, that goes to ground aswell (earth the harness)

Q: one is CPS, and what is the one right next to it for?

The other is the plug goes too No. 6 spark plug lead (near the cap), it has a plastic hoop around it that sends pulses to the ecu I believe.

There you go!

[Jean]

Ahh yes, the spark plug wire pulse connector.

Thank you.

[Jean]

So, looking a the rectangular C101 it's all pretty straight forward except for the pins 2 and 15.

Does the oil level sensor have a static and dynamic levels? I don't understand that. Pin 15 and 2 on the rectangular c101 are for Oil level Dynamic and Oil level Static.

1 is blue (D+)
2 is blue/purple (Oil level static)
4 is white/grey (Coolant)
6 green/yellow (power fused)
7 green/purple (fuel pump)
8 black/yellow (power on start)
10 green (power not fused)
15 blue/white (oil level dynamic)
16 blue/grey (oil pressure)
17 white/blue (si reset)

[Jean]

Ok, I spent about an hour on google trying to find b35 engine harness plug pins and found nothing...

Something like this but for e32/e34 b35 cars would be great -


The two ETMs I downloaded do not have this chart for some reason?!

In the E32 ETM I found this, but does not list the wire colors / functions....

[Jean]

Ahh damn, so the harness that I got was obviously modified..... found two more wires on it that were cut. This sucks.


Ok so I found another cut wire on the harness. Trying to identify the ends.

Ignition coil and grounds.


Temp sensor


o2 sensor, purge valve? and alternator wires?


Cut wire #1


AFM, TPS and ICV ?



Cut wire #2

[Doughnut]

Brown/green in your last pic, goes to the oil pressure switch, will have a two pin plug but will only use one pin. Switch is on the back of the head if it's a b35.