Followup. I found that the trailer lighting was pinched under the tailgate, probably causing a ground and melting the wiring, at least when I stepped on the brakes.
If I stayed on the brakes too long, combined with the tiltwheel moving, it may have been too much for the wiring.
Now the ABS light is on too.
If I stayed on the brakes too long, combined with the tiltwheel moving, it may have been too much for the wiring.
Now the ABS light is on too.