Electrical issue-possible SAM Failure

So I made a newbie mistake. I needed to power a relay for a set of driving lights. I grabbed power from the main power lead going to the front fuse block. Also used the factory ground. My lights powered up no problem and thought nothing of it until I went to go lock the doors. Nothing. Put the key in and the van started right up. No windows, no power door locks, no radio, no a/c.

Disconnected my installed relay.
Disconnected the battery.
Let it sit for 2 hours.
Reconnected and now the wipers are going on their own.
I don’t currently have a scan tool.
All fuses seem to be in tact.
Not sure where to go from here.

Sounds like about the only place to go from there is to a dealer and let them use xentry to check your SAM. If you have to replace your SAM.... I'm pretty sure they have to code the new one to your van to make it work. So you're kinda stuck with having to go to dealer (or a shop that has the right scan tools and knowledge).

"Used the factory ground" .... verify that the grounds are fully/well attached.

Here are three helpful manuals. The full MB service manual for a 2007, their wiring schematics, and a 3rd party version of the wiring:
http://www.diysprinter.co.uk/reference/2007-sprinter-service-information.pdf <-- 2007 manual
http://www.diysprinter.co.uk/reference/2007-sprinter-wiring-information.pdf <-- official (19MB)
http://diysprinter.co.uk/reference/07_Wiring-sprinter-2500.pdf <-- 2007 wiring

Dig out your model year's fuse list and perhaps check them with a volt/ohmmeter, not just eyeball.
Given the above schematics, try back-tracking the wiper circuitry to see if there's a possible cross-connect (such as one strand of a wire's connection bridging the gap to an adjacent pin)

The door circuitry has its own "smarts" in the driver's door module ... most communication to the rest of the vehicle is over the CANbus (or LINbus).

For the future: under the driver's seat is a terminal strip just for this kind'a stuff.
It's under a little flip-cover, behind the rear corner of the driver's seat fuse panel:



--dick