2000 E450 SD (Goshen Shuttle Bus) tail and running lights problem
 

The tail lights, running lights, and panel switch lights (for wheelchair lift,fast idle,brake lock lights etc.)and back up lights (and caution signal) are not functioning. Turn signals, hazard,headlights and dome are okay. Do the tail lights and running lights run off the the engine battery or the side aux battery that runs the lift? HELP!!!!!!!!!!

First thing to do is check for blown fuses. Since several things are not working, a fuse is my best guess.