Partsource for schematics
Was told about this a while ago.... worked out well today......
Partsource, at least in this part of Ontario, Canada, will print you partial vehicle schematics for free.
I needed the schematic for the windshield wiper circuit on my '01 E350. Finally dropped by Psource near me today, they run Mitchell's 2010, so it was easy/fast to find/print.
So.... if you are needing some wiring help, and can get to a Partsource, they may be able to get you a schematic for what you need to work on.