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Trailer Brake Controller, occasional issues

1K views 3 replies 3 participants last post by  brulaz 
#1 ·
Have been having occasional brake controller issues:
Usually just "Check trailer wiring" and then it goes away.
Rarely "Trailer brakes disconnected" and then it returns after a while.
No rhyme or reason that I can see.

Prolly the trailer wiring somewhere, but just to be sure I thought I'd test the truck's circuit by running it without the trailer but with a resistor across the brake leads to simulate a trailer.

Measured a couple of brake drums and got 3-4 ohms across each, so figured about 1 ohm total for all four wired in parallel. Tried that with a big wire wound 1 ohm ceramic resistor but got the "Check trailer wiring", immediately. Same with two ohms.

Think somebody here suggested a 10 ohm resistor but I don't have one and that doesn't match what I measured anyway.

Any suggestions? Anybody know how the brake controller senses the brakes?

I'll be going over the trailer wiring anyway, have already replaced the plug, but thought it would be nice to definitely eliminate the truck first.
 
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#2 ·
I had a similar issue a few years ago and found that I had a brake wire that passed through the axle tube had rubbed through and was grounding as we were moving. While the truck is possible, I would look at the trailer first.
 
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#3 ·
Don't know if it addresses your issues, but there was a TSb a couple years ago for the brake controller...

TSB #08-082-16

Sam
 
#4 ·
Yup, it was the trailer.
(had the controller TSB done some time ago)

Not sure exactly where the problem was, but I replaced half the wiring (including that in the axle tubes), replaced all the crimp joints (some seemed loose) with soldered joints, and even replaced all the brake assemblies as I wanted self-adjusting brakes anyway (and had a broken wire at the backing plate junction in another trailer some time ago).

Problem solved.:grin2:
 
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