Trip
I wouldn't say the controller is bad....That is what they told me when I had my warranty problem with the new trailer! Now I have 2 good ones! It probably just isn't rated to handle the amps for 6 brakes. I don't think that is your problem. I would clean the plug like the other guys mentioned...an easy job. Try it ....if no fix then disconect the plug!(this will burn up some controllers if you don't) and pull your breakaway (check out the voltage on that battery first) and see if you can drag it. If so I would bet it is in the magnet dept. I would then maybe get a controller rated for the 6 axles. I went through the same song and dance with a new trailer. I even ran another wire to the brakes blaming the wire size....didn't help! It ended up being the oil coated magnets. I'm not real sure but if you get a short in one magnnet it will draw to many amps robbing from the others. I bet you will know a lot more than you wanted after you are done....

 

Brakes worked for a while. I discovered one dead magnet. Replaced entire backing plate, with identical unit from Dexter. That's when my problems started. If controller is bad, why would I get 12.5V at truck bumper plug? If brakes are wired in parallel, how would one brake pull voltage down so much? I have one dead magnet now, one brand new one, and four originals. I think I am going to go ahead and get a new controller, but I am not confident this will solve the problem.

I suspect that when you had the one bad magnet --you were not putting the full load on the controller, example 4 magnets vs 6 . And when you replaced the dead magnet your trailer system was now up to snuff, but now your controller, being for only 4 magnets, was inadequate --get the new controller that will handle all your axles. using the breakaway can be a good test . Or jacking up each wheel, and appling the brakes to test each brake's actions independently . I suspect you were only having 5 magnets working before whenyour brakes were working .

 

Actually brakes are wired in parallel, not series. (Bob, that one was for you. ) Each draws about thee amps for a total max draw of 18 amps which is a lot for the wiring that you are using. The fact that you DID have brakes however tells me that is not your primary problem. It is also possible that you have a dead short back there in the trailer brakes and that is why your voltage drops as you move away from the truck connection. Since it started when you installed the new brake assembly, start there. Don't pop for a new controller yet.

 

I know that. DUH, just had to repair mine. In fact, I even said each puck takes about 2-1/2 to 3 amps - - additive.

SenileBob

 

The fact that he has wires getting hot after he activates them for a minute ---it is drawing probably 18 amps, 3 amp per brake. If there were a dead short I would suspect with the guage wire he is using that the wire would burn out or a fuse would blow. Do you have any way of measuring the amps being drawn? Make sure that new brake is wired properly . Still think controller may be the problem . The old or your present controller probably had enough extra capacity for an extra brake (5 ) but when the (6)brake was added when you replaced the bad one It just couldnt supply the needed amps for all 6 brakes . I could be wrong, --have been before lots of times! Let us know what fixes it !!!!!!

 

As an aside ---- some long week end ---when you are over this ---- If you replace all your light guage wire with some heavier guage stuff you will have a little better braking action due to the brakes getting the full amperage because you eliminated the line loss. Besides, when you do it, things will probably be fastened/ installed better than the manufacture did it !!!!!
We are still waiting for what the fix was !!!

 

His wiring is so light that even with a dead short in the trailer it probably wouldn't pop the 40 amp fuse. There is so much voltage drop in that length of wire it simply warms it up some. Since it started when he changed out a brake assembly, I am betting on a dead short. Even possible the new magnet is defective.

 

No fix yet. Rained, and ground to wet to lay on. Going to start again this afternoon. Thanks to you guys, I have a plan.

1)Unhook all six brakes, meaure resistance in each magnet.
2)Hook brakes up, one at a time, and check voltage.
3)Rewire trailer brakes, solder all connections. As I have been under trailer, noticed wiring is old, spliced, brittle in places, etc.
4)Replace controller with Jordan Ultima 2020.(because of proportional cable)
5)Get on waiting list for Brakeman controller.

If 1,2,3 doesn't work, will be in the market for a small thermonuclear device, to put trailer out of my misery.

Did I miss anything? My brain is fried about this.

 

Sounds like a plan !
Good luck with your brakes , if you were here, we could just back it in my shop, and do it in the dry!
Living in Oregon we just put on our rubbers and a broad brim and go to work anyway . We do tend to shy away from laying in a puddle, and welding over head tho ! and nope we really don't have webbed toes.

 

Great plan - - except for number 5. You are going to love that Jordan so much you will not want to part with it. (That is just for Casey).

 

OK. Got some progress. First, can't pay any attention to ohms. Dexter customer service says magnets should show about 3.4ohms. Mine checked anywhere from 2.5 to 40, including one magnet open. Checked with both digital and analog meters. Dexter service dept says they never pay attention to ohms, only amp draw. Amp draw was very balanced, even on magnets showing high ohms. Bottom line, I think old wire, too many splices causing high resistance and insufficent voltage in main line at brakes. I have five good brakes now, one dead magnet. Still, rewiring trailer with 10ga main line and 14ga branch lines. Currently 16ga. Ordering Jordan controller.

Magnets come with wire molded into them. On two of mine, these magnet wires were spliced inside brake assembly, before wire exited out thru backing plate to trailer harness, and these connections were bad.

Lesson learned. On any 12v system with any age, I believe temp and current draw kills small wire, creating high resistance, low voltage. Also from Dexter, there are three points inside brake assembly, that need to be lubricated. Two of my rear shoes were frozen, and would not move.

Thanks for all your help and ideas. I guess if I knew anything about 12v, this would not have been so hard, but I'm sure a lot more familiar with brakes now.