Trailer wiring problem

I followed the instructions on miata.net to the T, including buying the same $39.99 Hoppy-Lite wiring box. I've got brand new LED lamps on the trailer.

Left side works 100%. Turn signal, brake lights, running lights.

Right side is getting constant 12V on the turn signal wire, so it's on all the time and the turn signal doesn't work.

Power is hooked up to battery directly (pos and neg).

I disconnected the wire from the right turn signal and it's still sending out +12V constantly on the right turn wire, even when the car is off.

Only thing I can think of us that the Hoppy Lite is borked. Did I miss something?

Sounds like the adapter box is bad. Make sure the power and ground wires are connected properly, and if that doesn't do it then get a new one. I got a similar adapter box at the local auto parts store when I did mine.