About driving lights not working, it's common for the up fitter to remove them and replace with strobes or LEDs. Remove the headlights and you will probably find the sockets just hanging there. Also if you Hi beams don't work, they may have cut in a headlight flasher, and you need to go back to factory wiring. Does the horn work? That's another common issue they didn't reconnect when removing the siren.
All three of these things were wrong on my 2014.