[AT] Trailer brake controller problems

[Len Rugen]

If it's a trailer, it's a ground problem. Almost
always.  I'm always loosing ground from one wheel or
another, making the trailer pull.  It sounds like you
are loosing something that is common between both/all
brakes.  

If your trailer lights don't flicker at the same time,
then you may have a loose connection on the power
supply or control lead to the brake controller.  My
truck has a re-wired harness, so I haven't had any
problems on that side.  Yet....