W123 Auto to manual swap
 

Gonna do the swap to my 81 soon. I've dug through the threads of others who have tried this but I have one unanswered question regarding the wiring. What about the neutral safety switch? Also about the backup lights? I assume these are the same.... I thought this was pretty much plug and play but I suspect the harnesses are different.

its just 2 wires for each switch ...
Neutral safety is not so needed ...

The back up light switch is on the 4-spd shifter.

You remove the nutral safety switch that was plugged into the auto trans. that switch has 2 wires and contacts for the back up lights, and two wires and contacts for the starter.

The cable/wires from the NSS come into the cabin area through the tunnel near the fuel peddle. they connect to a plug above your right knee behind and at the top of the tunnel carpet. unplug it, throw it away, then plug in the back up light wire plug from the reverse switch connected to the shifter.

Remove the grommet in the tunnel, degrease/wash it, reinstall it and fill the hole with RTV.

http://www.peachparts.com/shopforum/diesel-discussion/333235-need-help-nss-going-auto-manual-trans.html

http://www.peachparts.com/shopforum/diesel-discussion/333784-neutral-safety-switch-troubleshooting-84-300d.html

http://www.peachparts.com/shopforum/2442891-post6.html


Charlie

also search for posts from greazzer, he bought my old auto 240D and turned it into a manual 5 speed....and went through this exact same issue.

Thanks guys. LAst remaining issue I had to work out before swapping the manual tranny out of the 82 over to the 81.