Originally Posted by onthelake
Checked all the fuses in the TT and TV. Used a diagnostic tool on the TV connector and all circuits work when the brake pedal is pressed. Even the electric brakes worked when I towed the TT yesterday.
This may sound stupid but did ya check the bulbs?
Most "newer" vehicles have separate fuses for the towed vehicle.
You may have checked fuses for tv and not fuses for trailer.
Also if none of the above apply follow your wire harness under camper and you'll find a junction box and quite possibly a fuse.
Make sure all the wires are connected there.