Trailer Brake Wiring Fault Message

[Old Mustanger]

Thought I'd add a simple solution that may or may not work for you.... I was having this problem intermittently on the first day of my last long trip. That evening I squeezed the contacts of the trailer plug together a little, added some dielectric (actually I use petroleum jelly), no return of the issue for the rest of the trip or since. YMMV

[markcee]

Originally Posted by JRTJH

I know it's easy to mistype a thought and it's also easy to get confused when troubleshooting a problem over a long time period. (Can't see the forest for the trees)...

The above two comments identified in red, directly contradict each other..... In the first, you state his truck DOES NOT engage your trailer brakes and in the second, you state his truck DOES engage your trailer brakes.

As Marshall suggested, I'd hitch the truck to the trailer, and, if the battery is fully connected, leave the 7 pin connector DISCONNECTED, pull the break-away pin and see if the trailer brakes function by pulling forward. The brakes "SHOULD" lock up and prevent the trailer from moving, after about a 3-4 foot distance.

If you want, then reinsert the pin, connect the 7 pin umbilical, install the velcro strap and tow the trailer. It "SHOULD" have "unlocked brakes initially" and they should function when the truck brakes or the brake control hand lever are engaged.

Thanks John and Marshall and everyone else that commented! I will do the breakaway test and see how it goes.

And yes....I did mistype in my contradictory posts (the few beers I had pondering the issue was probably also a contributing factor!) Report 1 was correct: no go when his truck tried to brake my trailer and good to go when I connected my truck to his.

[markcee]

Originally Posted by markcee

Thanks John and Marshall and everyone else that commented! I will do the breakaway test and see how it goes.

I just completed the test. The trailer brakes function fine when I pull the breakaway cable. Just as advertised, pulled ahead a few feet and they engaged fully.

I attached the umbilical back and cinched it tightly to the cover with a strap and pulled forward again - still no trailer brakes. The ITBC meter pops up and indicates activity when the trigger is squeezed but the gauge (power/effort meter) goes blank after a few seconds and more times than not the trailer brake wiring fault message appears. I DO feel braking during the brief periods (usually only a second or two) that the meter shows activity.

I see what you mean now about the plug....it is a pretty sloppy fit. I also tried winding a few turns of duct tape around it to tighten up the fit. It fit nice and snug then, but still no dice.

[LHaven]

Originally Posted by Old Mustanger

Thought I'd add a simple solution that may or may not work for you.... I was having this problem intermittently on the first day of my last long trip. That evening I squeezed the contacts of the trailer plug together a little, added some dielectric (actually I use petroleum jelly), no return of the issue for the rest of the trip or since. YMMV

I had a problem recently with a horse trailer showing no right blinker/stop function, squeezing the trailer plug didn't take, and neither did contact cleaner. Instead, I worked a hook in behind the truck connectors and spread them slightly, and got solid contact.

[markcee]

Originally Posted by LHaven

I had a problem recently with a horse trailer showing no right blinker/stop function, squeezing the trailer plug didn't take, and neither did contact cleaner. Instead, I worked a hook in behind the truck connectors and spread them slightly, and got solid contact.

Yeah, was thinking of spreading the male truck end contacts apart a bit and seeing what happens.

But curious....does the fact that the breakaway activates the brakes mean my wiring is good at the wheels back to the junction box? If so, would that indicate the last remaining link, and likely trouble spot is the umbilical (seeing as my truck was able to activate the trailer brakes on a different TT?). If so, curious about the best replacement for a Ford. I think I read in previous posts that a Bargman was a good match. Do you think this should be my next step??

[flybouy]

Originally Posted by markcee

Yeah, was thinking of spreading the male truck end contacts apart a bit and seeing what happens.

But curious....does the fact that the breakaway activates the brakes mean my wiring is good at the wheels back to the junction box? If so, would that indicate the last remaining link, and likely trouble spot is the umbilical (seeing as my truck was able to activate the trailer brakes on a different TT?). If so, curious about the best replacement for a Ford. I think I read in previous posts that a Bargman was a good match. Do you think this should be my next step??

from what I've read thus far it sounds to me like it's an issue between the truck and the the junction bow where the trailer's umbilical connects.

1. Your truck, and a known good truck won't work on your trailer.
2. Both trucks work on another trailer.
3. The emergency breakaway switch will operate your trailer brakes (this is evidence that the brakes in fact work and receive voltage from that point to the brakes)
4. the only missing link in my mind is the umbilical.

Wish I could help you with which plug to buy but I replaced mine on the F150 KR 10 years ago and I can't remember what I had for dinner last night.

[Javi]

This sounds like a problem I had several years ago with another trailer.

The factory 7-way plug on my truck was a premium Bargman supplied by Ford but the trailer plug was a cheap Chinese knockoff the Keystone uses.. I'd be driving down the road and get a warning that trailer was disconnected, or it would not apply the brakes.. Finally I bought a NEW Bargman plug & cord and replaced the cheap junk from Keystone.. Never had another issue... Just make sure you get a REAL BARGMAN not a Bargman STYLE..

[markcee]

Thanks guys. New Bargman brand 7-way ordered. Hopefully this will resolve the issue!

[Todd727]

Did you pull the brake drums and look at the wiring inside the drum to the magnets? I chased the same issue only to find that the wires were rubbing inside the drums. This is the most fragile part of the whole system and will always be the first place I look for this issue.

[RoadToad]

We had same problem on our Cougar.
Replaced Keystone whip with this one.
Towed over 2K miles since.
No more problems.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[jdl636]

Dielectric grease is a NON conductive grease used to seal out water. Incorrect application can inhibit not improve connections. I have attempted to link a video.

https://youtu.be/-542IYGBbpg

[LHaven]

Originally Posted by jdl636

Dielectric grease is a NON conductive grease used to seal out water. Incorrect application can inhibit not improve connections. I have attempted to link a video.

Thanks for the reminder. What I use for this application is DPL spray lube. Smells suspiciously like WD-40, but supposedly has some extra oomph that removes corrosion on electrical connectors.

[Mikelff]

Had similar issue and found connections inside truck plug were loose causing intermittent braking issues. Tightened up blades in truck plug and posts on trailer plug were making a TIGHT fit and issue solved. Couldn’t tell by naked eye that they were not making a good connection. I made sure all pins fit tight in plug. Had to make some slight adjustments to trailer plug posts to make sure they all fit properly but after that, no more issues. Sounds like you have already decided to replace truck plug and trailer plug and cord so when new hook up arrives make sure it all fits tight. Safe travels!

[markcee]

Thanks for the additional replies all.

I ended up ordering this Bargman 7-Way pigtail. I went to the storage place this morning and swapped it out. I found that my new cable had the exact same color wires as the original one. I snipped off each of the incoming pigtail wires, routed in the new pigtail and one wire at a time, crimped things back together.

Put the battery back and fired things up and I obviously do not have the wires matched correctly, even though the colors all correspond. The following occurs:

* Truck detects trailer connected but I get a right turn signal fault on the trucks display.

* Turn on left turn signal and all I get are the trailer reverse lights flashing on both sides

* Turn on the right turn signal and every light on the trailer blinks...lol

* Rolled forward with the trailer and still get no braking (at most just for a second or two again)

* I did NOT however get my original 'trailer brake wiring fault' message

Is there a way for me to determine what trailer wire in the junction box does what?

I was thinking of trying to cut apart my old pigtail's molded connector so I can see where each of those colors is pinned.

[cliff]

Had the same problem with our Montana. Get a small screwdriver and insert it into both sides of each pin and bend both metal pieces towards each other. Over time the contacts open and can cause the intermittants you are describing.

[ssdavies]

Every time I get the check brake wiring error message there is a brake magnet wire clip that failed to hold the wire away from the drum, and allows the wire to short out to ground. The truck brake controller will disconnect itself from the circuit to protect itself. It’s a pain in the neck, but pulling the wheels and hubs is the easiest way to chase the wiring issue. Just checking the brake magnet resistance doesn’t always work if the wire isn’t grounded against the hub when taking the measurement. Good luck, hope you find the problem.

[RoadToad]

Originally Posted by markcee

Thanks for the additional replies all.

I ended up ordering this Bargman 7-Way pigtail. I went to the storage place this morning and swapped it out. I found that my new cable had the exact same color wires as the original one. I snipped off each of the incoming pigtail wires, routed in the new pigtail and one wire at a time, crimped things back together.

Put the battery back and fired things up and I obviously do not have the wires matched correctly, even though the colors all correspond. The following occurs:

* Truck detects trailer connected but I get a right turn signal fault on the trucks display.

* Turn on left turn signal and all I get are the trailer reverse lights flashing on both sides

* Turn on the right turn signal and every light on the trailer blinks...lol

* Rolled forward with the trailer and still get no braking (at most just for a second or two again)

* I did NOT however get my original 'trailer brake wiring fault' message

Is there a way for me to determine what trailer wire in the junction box does what?

I was thinking of trying to cut apart my old pigtail's molded connector so I can see where each of those colors is pinned.

Her is the wiring diagran.

https://www.etrailer.com/question-41784.html

[RoadToad]

If you don't have one, a test light probe is essential.
AutoZone, Advance Auto, Amazon.

[RoadToad]

The screwy symptons suggest a Gnd might missing

[markcee]

Originally Posted by RoadToad

Her is the wiring diagran.

https://www.etrailer.com/question-41784.html

Thank you for the pic, it was a big help....I compared this to the standard 7-way plug diagram I was using and it appears the Bargman color coding is different. Based on what I'm experiencing it would appear to match up to the wires i have in the wrong location.

In comparing the charts I believe I have pins 1, 2 and 4 correct and the rest need to be adjusted.

Don't think this will affect my original no brake issue though