ChooChooMan74 wrote:
Brake lights, turn signals, and 4 ways use the same wire and filament on the trailer. If the turn signals and 4 ways are working properly, and just the brake lights not working, I suspect that the issue may be your 3 to 2 converter.

I opened up the work that the mechanic did. everything looks good. The car ground ties into the 7 way plug. All plugs are tight. I see no issues here.
Note that turn signals do not work. i.e
- running lights work. This includes dimming the 3 way brake/running light bulbs
- electric brakes work
- left and right brake light/turn signal are intermittent
I have to think it's the 3 to 2 converter