Have you checked the fuses under the hood and the ones under the seat? If you’ve applied 12v to the brake light wire then you know you’re good to there. Since the brake lights tie into the cutaway, you’ll have a fuse upstream. To my knowledge, with the exception of the ignition interlock, TB doesn’t undo the circuitry when they build the bus.
If you can’t find a fuse (my bet is in the one under the seat) you can contact Daimler for assistance. You’ll need the VIN. You might just try James Smolder. It’s been a couple years since I emailed. He is very responsive, so if you don’t get something in a day go to the Thomas Built site and look for a customer support number. His email is
I think your problem is in the cutaway area so look there first