Referencing this thread: Mechanical to Electronic Speedometer Conversion

I am in the process of doing an OM606 swap and then a 722.6 swap. I am getting all of my ducks in a row so there are little to no surprises when I do the swap.

The 722.6 does not have a mechanical speed output so the speedometer will need to be swapped for an electronic version. I have an ASR speedometer from a W124. The ASR isn't a big deal if you do not care about a useless idiot light that will never light up(unless you wire it for something else).

The speedometer is fully electronic. I need to determine how the 400E's speed output works any knowledge will be beneficial to me and any other W124 owner that does a 722.6 swap.

I will be going back to the junk yard to figure out the 400E in a week and grab any and all parts necessary.