I was wondering if there was anyway i could get a wiring schematic for a A518.

 

The following is for a '93 W250 with the A518. Hope it helps. (You may have to zoom in even after enlarging the images).

Cable routing and plug locations . . .





And wiring associated with the OD . . . .

(Unless I'm mistaken, once vehicle speed sensors, trans fluid temp sensors, etc are set, the PCM grounds the light-grey wire of the OD solenoid. The ignition switch applies 12vdc to the dark-blue wire).



Park/Neutral switch . . .



And transmission thermo switch . ..

 

Dang David!!! You The MAN!!!