On the way home Sunday from our last outing our brake controller reads a short in the system. We made it home safely, but the brakes were in & out the whole way home.I used my test light to check the brake wire to positive at the 7-pin connector and it would light. I'm not sure this is a good test though, as it may have only completed the circuit.If I use my ohm meter, could I narrow my search to the truck or the camper? If it's in the camper, I expect I could then remove each drum's magnet from the circuit by cutting the wires leading to the drum to find which is having a problem.I'd like to avoid having to pull each hub to check the wires inside... I just packed the bearings last spring. I could do it, just trying to avoid it if I can.Now that I think about it... Could I disconnect the brake system's ground then test the brake wire to positive?As you can see, I need assistance from others more experienced. Thanks in advance for your help!Happy Camping!John.

MegaJohn wrote:On the way home Sunday from our last outing our brake controller reads a short in the system. We made it home safely, but the brakes were in & out the whole way home.I used my test light to check the brake wire to positive at the 7-pin connector and it would light. I'm not sure this is a good test though, as it may have only completed the circuit.If I use my ohm meter, could I narrow my search to the truck or the camper? If it's in the camper, I expect I could then remove each drum's magnet from the circuit by cutting the wires leading to the drum to find which is having a problem.I'd like to avoid having to pull each hub to check the wires inside... I just packed the bearings last spring. I could do it, just trying to avoid it if I can.Now that I think about it... Could I disconnect the brake system's ground then test the brake wire to positive?As you can see, I need assistance from others more experienced. Thanks in advance for your help!Happy Camping!John.Do any of your wires pass through the axle? Very common issue of insulation chafing at that point causing an intermittent fault.You can replace the wiring, or sleeve it in plastic conduit to keep it away from sharp metal edges.Dollars to donuts that is where the issue is, unlikely to be the truck.

happened to me twice, was a wire rubbing the drum close to the magnet. Use a compass to check each wheel for magnet operation, if that does not help then Jack wheels up one at a time, engage brakes with the breakaway, spin the wheel. might be a good time to do a bearing pack and inspection anyway.

kaydeejay wrote:Do any of your wires pass through the axle? Very common issue of insulation chafing at that point causing an intermittent fault.You can replace the wiring, or sleeve it in plastic conduit to keep it away from sharp metal edges.Dollars to donuts that is where the issue is, unlikely to be the truck.Thanks for your help. The wires DO pass though the axles... I'll check that first! ;)Happy Camping!John.

SDcampowneroperator wrote:happened to me twice, was a wire rubbing the drum close to the magnet. Use a compass to check each wheel for magnet operation, if that does not help then Jack wheels up one at a time, engage brakes with the breakaway, spin the wheel. might be a good time to do a bearing pack and inspection anyway.Thanks for your suggestions.I am trying to avoid removing the drums as I just had them off to repack bearings & inspect brakes in the spring... removing them again would mean replacing the seals also. Everything looked in order and held in place in the spring... but I could have missed something.I like the campass trick and will have to remember that one if needed. ;)Happy Camping!John.

MegaJohn wrote:kaydeejay wrote:Do any of your wires pass through the axle? Very common issue of insulation chafing at that point causing an intermittent fault.You can replace the wiring, or sleeve it in plastic conduit to keep it away from sharp metal edges.Dollars to donuts that is where the issue is, unlikely to be the truck.Thanks for your help. The wires DO pass though the axles... I'll check that first! ;)Happy Camping!John.x2, Most likely place for failure

Brake Controller Showing Short in the System | Good Sam Community

RCMAN46
Explorer
Jun 05, 2013
MegaJohn wrote:
After much frustration and checking the wires in each hub (no issues found), we purchased another controller. About 450 miles later, we've had no problems with shorts.

Thank you to all who responded.

Happy Camping!
John.

What controller did you buy. I suspect you still have a brake issue and lets hope it does not come back and bite you in a bad way.

I am basing my response from one of yours last winter.

"I had a spare brake controller for the truck and changed it out. Our primary controller is a Hayes Genesis... the spare is a Draw-Tite, but I don't recall which one.
We hooked up the camper and the brakes seemed to work at first… then stopped working before we got on the road. "
MegaJohn
Explorer
Jun 05, 2013
After much frustration and checking the wires in each hub (no issues found), we purchased another controller. About 450 miles later, we've had no problems with shorts.

Thank you to all who responded.

Happy Camping!
John.
Sluggo54
Explorer
Dec 12, 2012
I have been down the road of chafed wires inside the axle. I have also had the socket on the truck partially disassemble itself, causing intermittent shorts and opens.
LAdams
Explorer
Dec 11, 2012
MegaJohn wrote:
I don't mind so much pulling the hubs off... but would like to narrow my search to one or two instead of pulling each one to find the last had the short.

Yeah, unfortunately there is no easy way to do this - if the new controller doesn't solve the problem, then you'll have to pull the hubs one at a time... A bit tedious I know but it may become necessary... Hope you find the problem without too much difficulty and aggravation...

Les
Steamguy
Explorer
Dec 11, 2012
just me wrote:
... install a resettable breaker, get rid of the FUSE in the brake system...

Do NOT EVER put a fuse or breaker between the controller and the brakes! If the fuse or the breaker opens under load, then YOU HAVE NO BRAKES! How do I know this and why am I shouting? It happened to me! The bonehead who wired my system up (a couple trucks ago) put in a thermal breaker between the controller and the brakes, and he put it under the hood. So it's a hot day, I'm in the mountains on a curvy road, and suddenly I have no trailer brakes...! Talk about having your hair stand on end! Once I finally got pulled over and my heart rate returned to normal, I found and fixed the problem.

The brake controller itself is fed from a fused line, and your controller is made to handle a dead short with no problem. Most of the really cool, modern ones (like yours) can indicate a fault. The thing is, most of these faults are intermittent, and your controller will continue to send regulated current down the line in spite of the fault.

But please, for your safety, don't put a fuse, fusible link, or breaker between the controller and the brakes.
facory
Explorer
Dec 11, 2012
If you haven't found the 'smoking gun', like you said, the short is still there just waiting to touch bare metal again. It may decide to do that just when you need your brakes the most. If it were me, I would have a qualified technician hunt down and fix the problem. Brake failure is a HUGE risk to all involved.
MegaJohn
Explorer
Dec 11, 2012
just me wrote:
When mine indicated a short I decided to stretch the wire in the axle by pulling on it, this will reposition the wire and the short went away temporally. So a new wire was installed out side the axle housing, no more problems. Also install a resettable breaker, get rid of the FUSE in the brake system and the charge systems.

Yeah, since I never found a "smoking gun"... I am concerned that there might still be a short someplace that I've not found and only moved the bare wire so that it is not shorting right now.

If the short comes back, my next step will be to rewire the brakes from the 7-pin wire harness to each drum.

Installing a fuse in-line is a simple change... I may look into that. If a separate run is installed for each drum, a fuse in each run would indicate where any future short can be found. What amperage rating would you recommend?

Happy Camping!
John.
facory
Explorer
Dec 11, 2012
Encountered the same problem. We found a broken wire inside one of the wheels. Put is back together and never another problem.
just_me
Explorer
Dec 11, 2012
When mine indicated a short I decided to stretch the wire in the axle by pulling on it, this will reposition the wire and the short went away temporally. So a new wire was installed out side the axle housing, no more problems. Also install a resettable breaker, get rid of the FUSE in the brake system and the charge systems.
MegaJohn
Explorer
Dec 11, 2012
spike99 wrote:
Many trailers use thin 12 guage wires (especially inside the hallow axle tubes) and their factory brake wiring is linear configuration as well. For each of my trailers, I simply remove the factory junk wiring and replace with thicker 10 guage double insulated duplex wiring. And, install in a STAR design configuration outside the axles.

If you want better than factory brake wiring under your trailers, upgrading to much better STAR configuration is worth it. Glad I do this upgrade to all my RV, Utility and boat trailers.

Yeah, if our problem comes back, I expect our next step will be to replace the wiring. If it comes to that, it may be best to run a seperate pair of wires to each drum.

Hopefully our problems are solved for now. ;)

Happy Camping!
John.