brake light wiring for hitch? Thomas short 1993

[jennynic]

Hi everyone. I own a 1993 Thomas short bus conversion. I did my short bus conversion a couple years ago and everything has been awesome. LOVE IT. I decided to have a towing hitch installed on the back but the fella installing it can't find the wiring for the brake/blinker/tail lights.

I suggested that they are in the compartment above the back door and travel down from each corner to the lights above the bumper, but he can't find them.

I remember a wiring bundle that came thru chassis above the windows behind the drivers side and connected to a fuse panel above the drivers seat. Does anyone have any idea where the back brake lights can be accessed to wire the hitch?

Or any work around ideas?

Thank you!
Jennifer