[AT] Trailer brake controller problems

[Al Jones]

I have been using my tractor hauling trailer today and the #($#$(*#$(
brakes aren't working right!  When everything is hooked up, the
indicator light is on, however it will occasionally flicker. When you
apply the brakes, sometimes the light stays on, sometimes it goes out,
sometimes it flickers, and at the same time the red light indicating
braking power may flicker or not come on at all.  Basically, sometimes
you have brakes, sometimes you don't. I am thinking I have a bad
connection in the plug that connects to the truck, but is there anything
else I should look at?  FYI I have sprayed the connection between the
truck and trailer with electrical cleaner and they LOOK good.  Does
there need to be a good ground between the truck hitch ball and the
trailer hitch?

Al