Electric brake problem

Hi
We recently took our camper trailer on a 2 week trip. On the morning of the 6th night, the right side trailer wheel was locked up, and only rotated the extent of free travel in the brake linings.
The electric brakes are operated through a Tekonsha unit, and worked fine for the previous Corner Country trip, and up until the lockup experience on this trip.
I cut the brake power wire to the trailer and this freed up the brake.
The rest of the trip was done without trailer brakes with no dramas, but after returning home, I reconnected the wire, and the wheel rotated without locking up. (2 weeks ago)
This morning, I was about to move the trailer, and the wheel was again locked up until the power wire was disconnected.
Before I start taking the wheels off, and pulling the hubs apart, does anyone have any thoughts on whether it would be a brake fault, or the Tekonsha controller?
Cheers
Ian