Z3 M44 to S52 Swap

[modifiede30]

I'm in the middle of swapping out my M44 to the S52 I had from my donor car I was originally going to fix up, and decided to part due to the title not being clear. I'm about to pull the M44 and noticed a key difference in wiring that is worrying me a little. On my S52 setup, the ABS main connector is wired entirely within the engine harness. However, on the M44, the ABS is on the chassis harness - both are totally different connections and the M44 has 6 lines while the S52 has only 5. I did notice that on the S52 there's a distribution block at the rear of the car to split the line between right/left whereas the M44 has separate lines. I assume this is a detail related to variations in the ASC setup between them. However, it doesn't resolve the chassis/engine harness issue. I had originally planned to carry over the ABS unit and the electronic controls from the S52 but now wonder if having the original M44 chassis harness connection not connected to anything is going to create a problem unless I move the entire chassis harness over as well (not what I was hoping to do given the pain this would add to the effort.

Anyone run into this before in any M44/S52 swap? Any suggestions?

[modifiede30]

After reviewing the wiring diagrams for the 2 cars in the electronics manual I found its clear the 2 harnesses differ significantly for the ABS/ASC controls and pump systems. I am now bummed I have to replace the entire chassis harness - good thing I took the one I had from the M-Roadster. Luckily I found the rear subframe on that chassis was pretty close to failure so likely wasn't a good candidate for my build anyway.