Harness Questions

[Smcmaster]

I've got an m52b25tu from a 2000 323i. The harness was cut while the engine was being pulled from the car. I've purchased an intact engine harness but the chassis connections aren't attached still. The guy kept that section in his car for his e46's engine swap. Ideally, I have plans to go to a u-pull it and just grab a section of the harness with the engine side x20 plug so that I can just plug it into my existing harness. Does this work?

Where can I find the chassis section within the e46's engine bay? Where does it connect to the harness?

If anyones got any help it'd be much appreciated.

Thanks

[TobyB]

The harness connections happen in the ECU bin with the DME and the DME fuse block- with 5 fuses.
Very few wires from engine and chassis cross- connect, (power, mostly)

www.bmwteka.com has diagrams. And some pictures, altho they're not always helpful.

However.

Your life would probably be easier in both the short term and
the long run if you got an engine harness out of a 525, and the DME bin connections as well.
And the throttle body and pedal, while you're there.
The M52TUB25 will run just fine as an M54B25, and MS43 is a nicer DME to install and modify.
MS42 wants an accelerator cable, has a throttle body from hell,
and seems to be really sensitive to air leaks.

Anecdotally... well, and then there's the 528 I sometimes drive...

t

[sweet3]

Your simplest option is to have an uncut complete engine harness on hand, and then use an adapter harness to get it to mate to your chassis fusebox plug.

The M52TU doesn’t use a round X20 plug, so don’t go looking for that connector, or you will just be looking for a long time.