Hello - we are experiencing the same issue with a brand new 2014 Adams LQ. Was your issue ever resolved? Has anyone else experienced their electronic brakes locking intermittently? 

It started off with the trailer pulling hard to the left while braking during descents. The dealer told us it was because our digital brake box was sending too much amperage to the brakes and recommended an analog type. He also replaced the back plates at that time. Although we were sketical, we decided to install an analog type controller. 

Next trip, 4 hours into the haul our brakes started locking up. Shook the trailer so hard the hub cap flew off. Continued until we got to our destination (intermittently). On way home, got 4.5 hours into trip and again they started to lock up.

Dealer is now saying we are setting the brake controller too high and I am calling B.S.!

All information is very much appreciated

Both of these issues sound like a mechanical problem, not an electrical. The brake magnet cannot be energised unless a voltage is applied to it. If only one brake is working or only one side, the wiring is wrong. If the wiring is correct, then the mechanical brake parts should be inspected.

The first thing to establish is which brakes are working and are they operating correctly? This is easy to establish by watching the tires when the trailer's brakes are applied on a gravel surface. They can be set to lock up with the over ride under this condition. If some are and another isn't, the first thing to check for is the correct star adjustment, if they are manually adjusted. After evenly setting them all, try the lock up procedure again and see if there is any difference in the operation. You may now be able to have all four opperating the same.

If a brake is too tight, or the linkage is worn, or a spring retainer is broken, the brake shoe can contact the drum as things heat up during the travels. This can cause a brake to drag and produce more heat within the drum than the rest of the brakes.

If your drag test results in an inoperative brake, which isn't the problem suggested by the OP, then the drum will have to be removed to inspect the brake components and trouble shooting the wiring.

An over tightened or burnt wheel bearing can also cause drag and excessive heat. We purchased a new trailer and within a couple hundred miles, two wheel spindles failed. The bearings were found to be over torqued and installed dry on the same side. Apparently some worker's lunch was waiting for him at the factory.

Any certified mechanic should easily be able to inspect and repair, the electrical bake system used on these trailers. The circuits are simple, the parts are few, easily inspected and replaced. You don't need a dealer who has never seen this problem, only a good mechanic willing to take a look.

Thank you both for your input. As you can imagine, I am beyond frustrated with this problem. Both situations I outlined could have ended with serious consequences to myself, my horses and to fellow travelers sharing the road.

We will continue to dig to find the cause, most likely with a mechanic now rather than the dealer and will post back with the outcome! 

Thanks for the follow up Trot-on.  Ours goes into the shop on Monday. Hoping they find something because not knowing if/when it will happen again is enough to keep me from using it

I will post what our outcome is as soon as we know.

Outcome of our last visit to the RV shop is that it is not the trailer but rather something in the rear antilock brakes on our truck. The are grabbing too hard for some reason.  We do feel that this really a possibility so the truck is at our mechanic.  My fingers are crossed!

An ABS interaction will not affect only one of the trailer's four brakes. If they are all electrically wired correctly, are mechanically sound and adjusted, each one will exhibit the same electrical reaction as provided by the controller. One cannot be magnetised any longer than the others. Any one that is not working correctly will be cooler than the others.

An ABS or controller problem will affect each of the brakes at the same time.

Agreed Beeoerdog but unfortunately most people don't jump at the chance to hand over their trucks for 4+ hours which is how long it takes for the problem to present itself.

Gard, I think I must have been unclear.  We thought the issue may have been the truck's rear ABS engaging (not trailer) causing the violent shaking. However, our mechanic has thoroughly inspected the entire braking system and does not see any indication of any brake issues. Back to square 1.