2009 t800, no power to high beam on one side

I am working on a 2009 T800, the driver called me after midnight saying the low beams were out on one side, the high beams on the other. This happened after a washboard stretch. There is no power at the headlight harness plug for low beams on one side, and some voltage bleeding through on one side between high and low.
There isn't a fuse or relay in the fuse box, and the column switch has little tiny wires so the power isn't going through there. There are no obvious damaged wires, so where can I hunt out power on this?

 

Well that's the issue, there isn't a fuse or relay in the box next to the column, under the hood, or in the battery box. With the headlights unplugged at the harness, there is no power. With or without them connected, it chimes constantly and displays a headlight malfunction message. A schematic would be a huge help, if KW wasn't 40 miles away, I'd just go and get one from my contact there.

 

I had the year wrong this is a 2011. There was a bad fuse in the under hood box, labelled "Chas node". I guess in some engineer's mind that means headlights, or KW provides a translation guide to their techs.
So, if someone stumbles across this while trying to solve goofy headlight issues, check the fuses in the underhood box, second row. All the rest are emissions related.

 

I have thoroughly checked it, I ohmed the ground (it's fine), and there was only power to one pin on each side, but I fixed it. This truck previously had a bad headlight, which may have caused the fuse to blow.
The harness runs down the left frame rail to just under the radiator, then splits to left and right. Ground returns through the full length of the harness and goes to the ground stud on the firewall.
I just wish the info for these trucks was as readily available as info for cars, dealerships here have multi-week backups on a lot of this stuff.