electric brakes

Is it possible for the controler to pass enough power that they apply enough to keep things rust free but not enough to be able to apply strong enough for any stopping power. Pulled non holding brake today after was told the controler was working and probably rusty. No rust at all but do not hold, camper was same way as this machinery trailer so it is not the wireing on the trailers. was spring they were working, first noticed problem with camper in July and had not been on road for 7 years so thought it was rust but then after that when I noticed it with the machinery trailer. Have gotten by for a while without them working and by law I do not have to have them as it is not heavy enough to even be required. Trailer is about 14 years old and the linings show no wear yet and are adjusted. So only thing I can come up with is the controler is not putting out enough power. Garage man said the controler was working and had to be trailer brakes but both trailers?

i dont know about how much power it puts out BUT you could unplug the trailer from the truck and use a 12v battery to hook to the trailer wire plug that goes to the brakes then try to pull the trailer a little with the brakes applied, that will tell you if the trailer brakes are good.

Grounding?

Iuse a batery charger to test the brakes on 12 volts it will lock them up if they work or at least you can hear the magnets engage if shoes are out of adjustment

the magnetic coils in the brakes can get worn and weak--check the mating face and if you see loose wires they need replacing

I'm not the most expert guy on electric brakes but I used to maintain 21 trailers for a contractor friend. Trailer brakes can be working perfectly one day and not the next..Here goes..
our magnets can get hot,and burn to the point they won't work..if you see blue metal,heat marks they may well need replacing. If they are working a little bit,the brake drums should show "rub wear" on the face of the drum and brake line drag marks on the drum braking surface.
You say they are adjusted,BUT if the brake adjusters and the swivel points are rusted or siezed,the brake shoes won't move. Strip everything off the back plate ,clean with wire wheel and then apply anti sieze to all pivot points and all contact points that shoe sits on.(Hint after a couple of years of doing these trailers and buying all the components,we found you can buy the entire brake(Backplate,shoes,springs,magnets,all assembled) cheaper than you could buy the parts..Carquest),thus all I needed to do with badly worn components was clip the wires,remove the four bolts and swap out the entire brake,bolt it, splice the wires and the labour saving cut the maintenance cost almost in half.
When you put the power to the brakes,you can hear the faint buzz sound and you know they are working
I;m not sure I would put full 12 volts directly to the magnets,your controller doesn't do that,probably only a few volts..just in case a wire gets hot and melts off. test your wires and determine which is the ground using the controller,then make sure you have a good clean ground. Also run a jumper cable from your truck to the trailer on clean metal surfaces,this will show you a lot..often everything works and you then know that a plug,or a wire on the ground side is not working and you can work from there..remember Magnets do go bad,but 90% of the problems in wiring is ground. If we had a trailer that we couldn't trace the wiring issue,we just ran new wiring harness,we made our own up as the contractor was an Electrical Contractor and we had six wire and seven wire spools..so 1) Ground 2) magnets) 3)wiring 4) siezed shoe
Good luck,let us know

That's some good advice, thanks, my trailer brakes don't seem to work or work sometimes! I'm sick of working on them, they buzz but don't seem to help stop any, I gotta get looking at them soon, I'll need the trailer again in April.

Yes, some controllers are worthless. For years I cussed all electric brakes as being useless. The last truck I bought came with a timer control. It had a little bit more power than what I was used to, but was very irritating on how it worked. I installed a different controller and the first time I used it I about kissed the windshield! Its a Tekonsha Voyager, that thing has enough power to stop the whole outfit just on the trailer brakes. This was all with the same trailer.

There is nothing stuck in them and they do show as they were trying to work. Just wondered if a controller could get week with age without quiting completely, That is the one thing that I do not know that I need to know.