Trailer Brake Wiring Fault Message

[markcee]

On Friday I pulled our trailer home about 30 miles from the local Camping World where it had been parked for the last month to get assessed for some (unrelated to what I'm reporting here) warranty repairs. On the way out of the lot I tested my trailer brakes and all was good. However, during the last mile of my trip I noticed that the truck seemed to be doing a lot of the stopping, this was soon followed by a 'brake wiring fault' message on the truck's display. I also observed that the the brake 'output' meter on the dash display lights up upon brake application (either foot pedal or trigger) but then quickly cuts out. I got the trailer home OK and am not sure what to look for so would appreciate any suggestions.

Some other info - we had some torrential rain here earlier in the week, so the trailer (and my truck for that matter) were exposed to a lot of water. I checked the 7 pin plug on the trailer and truck but didn't see any obvious signs of water intrusion. For the hell of it, I did lube up the connection points with some dielectric grease.

After lubing the contacts I hooked up and plugged in the trailer and received the fault message again. I took it for a local ride and see the same thing with regards to the Output meter going in and out. Initially I would not feel any trailer brake grab even when the Output meter showed activity, but about 1/2 mile into the ride I did start to feel some brake grab and the brakes actually seemed to stay engaged more than just briefly. So....do you think it's possible it was just wet components and perhaps if I continue to drive braking will continue to improve? Anything else I should look for that doesn't involve pulling the wheels off?

Thanks in advance!

[JRTJH]

There is a "7 pin connection" on the back of the one that's mounted on your bumper. It's a different style with a locking tab on it. On most, there's an O-ring to seal the interior of the plug from water intrusion. If that plug is not "completely plugged together" or is there's any water/condensation on the pins, you may have an issue there. If you get on a creeper, slide under the rear bumper of your truck, you should be able to easily locate the plug. Separate it, dry it well, add some di-electric grease and then reconnect it as securely as you can.

If that doesn't so the trick, sometimes there is a "brand difference" between what the truck manufacturer and the trailer manufacturer use for their 7 pin connectors. Sometimes the different brands are "just slightly off measurement" enough that the pins won't seat securely in the holes.... When that happens, sometimes you can clean them enough to get the two pieces to seat properly, sometimes, you may need to change out the trailer connector for the same brand as the truck connector....

Keystone uses the "lowest bid umbilical set" so if it comes to changing it out, I'd opt for the "upgrade" to the truck brand connector.

[markcee]

Originally Posted by JRTJH

There is a "7 pin connection" on the back of the one that's mounted on your bumper. It's a different style with a locking tab on it. On most, there's an O-ring to seal the interior of the plug from water intrusion. If that plug is not "completely plugged together" or is there's any water/condensation on the pins, you may have an issue there. If you get on a creeper, slide under the rear bumper of your truck, you should be able to easily locate the plug. Separate it, dry it well, add some di-electric grease and then reconnect it as securely as you can.

If that doesn't so the trick, sometimes there is a "brand difference" between what the truck manufacturer and the trailer manufacturer use for their 7 pin connectors. Sometimes the different brands are "just slightly off measurement" enough that the pins won't seat securely in the holes.... When that happens, sometimes you can clean them enough to get the two pieces to seat properly, sometimes, you may need to change out the trailer connector for the same brand as the truck connector....

Keystone uses the "lowest bid umbilical set" so if it comes to changing it out, I'd opt for the "upgrade" to the truck brand connector.

Thanks John. Checked the backside of the bumper 7-pin and all is tight as a drum. No exterior moisture, no looseness in the connection.

We towed about 5K miles with this truck and trailer setup....and another 2K with another Ford (also a 2019), so presumably same 7-pin connector and zero trailer brake issues. Still possible it's a variance between the Ford and Keystone connection points? Doesn't seem likely......but open to discussion!

As a side note, we did have our axles replaced this summer. We had a couple of blowouts. The cause was identified as bent (defective) axles. Although the brakes worked fined during the subsequent 3K of towing after replacement, perhaps there is some mangled wiring inside the axle tube or hub? Either way, sounds like another pain in the *** for me...lol. Wife already talking about selling and going back to commercial air. I love the over land travel, but have to say, unless you are a mechanic this sh*^ gets old quick! I sure don't mind to tinker, but hell, for 35K-40K, don't you think you should be able to travel a couple of years without spending 2-3 months in the shop. I don't care if it's under warranty or not! OK, semi rant over...lol

[JRTJH]

If your axles were replaced, the mechanic may have used "non-waterproof crimp connectors" to connect the brake wiring. If so, the problem may be corrosion in the crimp connectors. Copper wires, when subjected to wet weather will corrode. That changes the resistance on the brake circuit and the Ford trailer brake controller will sense that resistance change as a "trailer brake fault" and throw a code.....

Check the connections at the back of each trailer wheel. I'd suspect they are the typical "red, blue or yellow" crimp connectors. If so, that may be your problem....

The correct connectors to use are ScotchLock waterproof crimp connectors. You can buy them at NAPA or most "well stocked auto parts stores. They look like this photo (3 wire type) and will have a "cream filled silicone" center.... Sort of like chocolate covered cherries.... LOL

[ChuckS]

A few quick checks with a multimeter set to ohms scale...
.. on the RV side 7 pin plug measure between pins 1 and 2 total resistance
.. you are looking for around 0.8 ohms of resistance

This quick check is measuring the total resistance of all 4 brake magnets in parallel... each magnet should measure around 3.2 ohms so 4 in parallel would be 0.8 ohms of resistance

The IBC (integrated brake control) looks for a given amount of resistance to tell the circuit something is connected to it

The above ohms measurement won’t tell you which brake magnet is causing the issue but it will tell you what the IBC is seeing

If your ohms reading is way off from 0.8 ohms Id check..
... RV side plug backside wire connections
... junction box on RV usually in pin box area if fifth wheel

Also a bad ground wire on any of those 4 magnets will cause IBC to think there is no trailer connected

It’s just a quick check but may shed shed some light to where to begin

[markcee]

Originally Posted by ChuckS

A few quick checks with a multimeter set to ohms scale...
.. on the RV side 7 pin plug measure between pins 1 and 2 total resistance
.. you are looking for around 0.8 ohms of resistance

This quick check is measuring the total resistance of all 4 brake magnets in parallel... each magnet should measure around 3.2 ohms so 4 in parallel would be 0.8 ohms of resistance

The IBC (integrated brake control) looks for a given amount of resistance to tell the circuit something is connected to it

The above ohms measurement won’t tell you which brake magnet is causing the issue but it will tell you what the IBC is seeing

If your ohms reading is way off from 0.8 ohms Id check..
... RV side plug backside wire connections
... junction box on RV usually in pin box area if fifth wheel

Also a bad ground wire on any of those 4 magnets will cause IBC to think there is no trailer connected

It’s just a quick check but may shed shed some light to where to begin

Thanks for the info. I just did some troubleshooting based on your info. Being an electrical moron, I wasn't sure what Ohm setting to use so I ran thru them all. Two of the 4 settings showed a reading, pics are attached below.

In addition, I opened the junction box on the trailer frame rail. All connection points inside appear secure. I tugged on all the wire nut connections and nothing was loose.

Finally, I examined the axle tube entry points of the wiring at all 4 tires, as well as the connection on the back of each hub. All appeared damage free and all grommets were in place. I've attached a couple of pics of this as well.

Appreciate any feedback. Thanks again.

[ChuckS]

Your pic.. always set ohms scale to lowest setting for “most” measurements you’d be making...

The .6 resistance reading tells me that “electrically” the four brake magnets and wiring from front to back appear to be intact and have good continuity..

It doesn’t tell you how much amps each magnet is drawing when brakes are applied but tells me that your truck IBC “should” be seeing a good steady signal from the magnets thru the wire harness to 7 way plug connection.

There have been a myriad of posts on issues with their IBC showing intermittent “trailer disconnect dash message” and on all 3 of the common trucks used to tow with...

Your system can be tough to troubleshoot because many of the IBC units require the truck to be in gear, in motion and seeing feedback from the ABS as well as motion..

I’d have to really look hard at the 7 way connection from RV plug to Truck... Measure the resistance reading from brake and ground pins on front to back side of the truck and RV pins to wire connections

[markcee]

Originally Posted by ChuckS

I’d have to really look hard at the 7 way connection from RV plug to Truck... Measure the resistance reading from brake and ground pins on front to back side of the truck and RV pins to wire connections

Thanks for the info. As for your next suggestion, I'm having trouble following where I am supposed to check exactly. Can you elaborate? (Like your explaining to a dummy, please!)

Thanks again.

PS...I'm having a buddy stop over tomorrow with his truck. We both have our trailers at the same storage just up the road. We will flip/flop and he'll hook up to my trailer and I'll hook up to his and we'll see what happens.
I suppose this will narrow things down (unless of course he can brake my trailer AND I can brake his), but I'd still appreciate your further explanation as I'm interested in learning these things

[Voyager]

I had the same issue, it turned out to be a wire that had been rubbing on the propane line and was causing a short, it was not worn right through but almost and it was very difficult to diagnose, wrapped some tape on and plastic shielding and problem solved. Good luck.

[xrated]

I've written about this very issue before, and the issue that I had on my Keystone Toy Hauler. The 7 pin connector on the truck side vs. the 7 pin connector on the trailer side, and the possible issues regarding them. Many times they are two different brands of connectors. Theoretically, they should both be compatible and work together well. Realistically, since they are two different brands made by two different manufacturers, they sometimes don't. I fought the exact issue that you are having for several months on my previous trailer, the Keystone that I had. I replaced the Ford connector on the truck.....no happiness, and then I replaced the trailer 7 pin and still no happiness. I was getting pretty frustrated with it all, and by chance, I decided to try and make sure that the plug from the trailer was staying "tight" in the connector from the truck. I bought some velcro straps and after I plugged the trailer into the truck, I took one of the velcro straps and making sure that the plug was fully inserted in the truck....wrapped the velcro strap completely around the plug AND the connector door/cover and strapped it tight. That insures that the plug cannot wiggle around inside the connector....and guess what! I never ONCE had an issue again with the trailer brakes not working. It totally solved it for me.

It would certainly be worth trying my "fix". The velcro straps are cheap and easy to try....and if it works for you, the headaches are over. If the velcro strap wears out of gets lost, just put another one on and keep going

[flybouy]

Similar experience as xrated. It was on my F150 when we bought it and was pulling a Forrest River trailer. I used a short bungee cord and it worked. Got to looking closely and the OEM truck receptacle looked like it had a very minor chamfer in the end. I filed off the end of the trailer plug to round it a bit and it worked fine.

I didn't like the look of the trailer plug (both my alteration and the contacts inside) so I bought a new umbilical and never had another issue. They are supposed to be universal but some brands don't play well with others.

[xrated]

Originally Posted by flybouy

Similar experience as xrated. It was on my F150 when we bought it and was pulling a Forrest River trailer. I used a short bungee cord and it worked. Got to looking closely and the OEM truck receptacle looked like it had a very minor chamfer in the end. I filed off the end of the trailer plug to round it a bit and it worked fine.

I didn't like the look of the trailer plug (both my alteration and the contacts inside) so I bought a new umbilical and never had another issue. They are supposed to be universal but some brands don't play well with others.

So very true. The differences between brands of trailer plugs are usually not visible to the naked eye and look just like any other brand. Unfortunately, tolerances in the plugs/connectors do happen from manufacturer to manufacturer and thus the issues sometimes. It's unfortunate, but as far as I know, we, as the consumer just have to try and figure it out and hopefully be able to.....and make it work, even if it involves using unconventional methods like I and others have done.

[ChuckS]

What I meant to mean by measuring continuity from truck to RV connections is..
... truck turned off and 7 way plug connected from RV
... you will need a jumper wire for this check.. about 6 foot or so light gauge wire.. such as 22 or 24... just something easy to work with
... connect one lead of meter to back side of truck 7 way brake pin
... connect other meter lead to pin box connection on same brake wire
.. measure continuity and wiggle 7 way plug while observing meter
.. do same for ground pin on truck 7 way to RV pin box grd connector

If there is fluctuation in your resistance reading while wiggling 7 way RV plug then you know you have an issue with poor connection at 7 way plug

And yes you could just go buy new 7 way receptacle for truck and 7 way plug for RV but I am not much for “part swapping”

I like to isolate and “know what the issue is and fix it “

The overall ohms reading you should see should be no more than 1.0 ohms resistance given the meter and small test lead resistance induced into circuit

With truck turned off the IBC shouldn’t not be sending any DC voltage to brake pin output on 7 way receptacle

[markcee]

Originally Posted by ChuckS

What I meant to mean by measuring continuity from truck to RV connections is..
... truck turned off and 7 way plug connected from RV
... you will need a jumper wire for this check.. about 6 foot or so light gauge wire.. such as 22 or 24... just something easy to work with
... connect one lead of meter to back side of truck 7 way brake pin
... connect other meter lead to pin box connection on same brake wire
.. measure continuity and wiggle 7 way plug while observing meter
.. do same for ground pin on truck 7 way to RV pin box grd connector

If there is fluctuation in your resistance reading while wiggling 7 way RV plug then you know you have an issue with poor connection at 7 way plug

And yes you could just go buy new 7 way receptacle for truck and 7 way plug for RV but I am not much for “part swapping”

I like to isolate and “know what the issue is and fix it “

The overall ohms reading you should see should be no more than 1.0 ohms resistance given the meter and small test lead resistance induced into circuit

With truck turned off the IBC shouldn’t not be sending any DC voltage to brake pin output on 7 way receptacle

Well, I did ask you to explain 'like you were explaining to a dummy'.....I guess I should have said 'blithering idiot', because I still have questions on your test.

1. What am I jumping with the light gauge wire? I don't see you mention attaching it anywhere....only see you mention the meter leads.

2. If I'm plugging the trailer into the truck, how am I to access a point (electrical contact or bare wire) to place the lead on at the truck end?

3. Figuring that on the trailer end I will be placing the lead on the appropriately colored wire within the junction box the umbilical leads to?

4. Am I OK to do this testing with the RV battery connected?

5. Regarding the continuity test I did earlier and posted pics of......does this rule out any issue with the wiring back to the brakes, such as a short?

Thanks....I owe you a cold one.

[markcee]

Originally Posted by flybouy

Similar experience as xrated. It was on my F150 when we bought it and was pulling a Forrest River trailer. I used a short bungee cord and it worked. Got to looking closely and the OEM truck receptacle looked like it had a very minor chamfer in the end. I filed off the end of the trailer plug to round it a bit and it worked fine.

I didn't like the look of the trailer plug (both my alteration and the contacts inside) so I bought a new umbilical and never had another issue. They are supposed to be universal but some brands don't play well with others.

Originally Posted by xrated

I've written about this very issue before, and the issue that I had on my Keystone Toy Hauler. The 7 pin connector on the truck side vs. the 7 pin connector on the trailer side, and the possible issues regarding them. Many times they are two different brands of connectors. Theoretically, they should both be compatible and work together well. Realistically, since they are two different brands made by two different manufacturers, they sometimes don't. I fought the exact issue that you are having for several months on my previous trailer, the Keystone that I had. I replaced the Ford connector on the truck.....no happiness, and then I replaced the trailer 7 pin and still no happiness. I was getting pretty frustrated with it all, and by chance, I decided to try and make sure that the plug from the trailer was staying "tight" in the connector from the truck. I bought some velcro straps and after I plugged the trailer into the truck, I took one of the velcro straps and making sure that the plug was fully inserted in the truck....wrapped the velcro strap completely around the plug AND the connector door/cover and strapped it tight. That insures that the plug cannot wiggle around inside the connector....and guess what! I never ONCE had an issue again with the trailer brakes not working. It totally solved it for me.

It would certainly be worth trying my "fix". The velcro straps are cheap and easy to try....and if it works for you, the headaches are over. If the velcro strap wears out of gets lost, just put another one on and keep going

Thanks for the info. Regardless of the outcome of this, thinking it may be wise to swap out my umbilical for a more Ford friendly one. In the meantime, I'll take some velcro strapping with me today when I do some testing.

[markcee]

So, here's the latest in my trailer brake saga. My friend and I headed to the storage yard today, results as follows:

He hooked his 2015 Chevy Silverado to my trailer and pulled forward....no trailer braking when trigger squeezed.

I hooked my 2019 Ford to his TT and pulled forward....trailer stopped immediately when trailer brake trigger squeezed.

So I guess there is an issue with my trailer....no surprise there as these things seem to be assembled from parts manufactured in China by 15 year old Elkhart, IN middle school dropouts....what a combo!

[xrated]

Originally Posted by markcee

So, here's the latest in my trailer brake saga. My friend and I headed to the storage yard today, results as follows:

He hooked his 2015 Chevy Silverado to my trailer and pulled forward....no trailer braking when trigger squeezed.

I hooked my 2019 Ford to his TT and pulled forward....trailer stopped immediately when trailer brake trigger squeezed.

So I guess there is an issue with my trailer....no surprise there as these things seem to be assembled from parts manufactured in China by 15 year old Elkhart, IN middle school dropouts....what a combo!

Personally, I wouldn't feel comfortable saying that test was conclusive. It seems to me that you have proven that the braking issue is an intermittent problem that does not show any type of consistent pattern of repeatability. Did you try your truck today also, on your trailer and did you try the velcro strap around the plug in connector. I'm obviously not saying that it has to be the problem, but it is, as I stated in an earlier post.....a pretty cheap way to do another test and see if the results are repeatable.

[markcee]

Originally Posted by xrated

Personally, I wouldn't feel comfortable saying that test was conclusive. It seems to me that you have proven that the braking issue is an intermittent problem that does not show any type of consistent pattern of repeatability. Did you try your truck today also, on your trailer and did you try the velcro strap around the plug in connector. I'm obviously not saying that it has to be the problem, but it is, as I stated in an earlier post.....a pretty cheap way to do another test and see if the results are repeatable.

Yeah, will definitely try the velcro but these results seem pretty consistent to me...my truck doesn't t brake my trailer, his truck does and vice versa....sight unseen, no tweaking, no nothing, plug and go. After my axle mishap I did drive almost 3K back home with no issue in braking.

I didn't try my truck today, but tried it for several miles after this problem was identified. Can't see how anything would change sitting in a parking spot for 3 days. The old school computer troubleshooter in me strongly indicates the issue being with my trailer wiring or brakes. Not trying to argue, but seems pretty conclusive from a rudimentary standpoint. What am I missing...and as always, thanks for input!

[flybouy]

The only thing I would have tried would be pulling the pin on the breakaway switch. That should apply full available voltage from the trailer battery to the brakes. Then when you move the trailer the wheels should lock up. That would isolate the trailer wire to between that switch and the brakes.

[JRTJH]

Originally Posted by markcee

So, here's the latest in my trailer brake saga. My friend and I headed to the storage yard today, results as follows:

He hooked his 2015 Chevy Silverado to my trailer and pulled forward....no trailer braking when trigger squeezed.

I hooked my 2019 Ford to his TT and pulled forward....trailer stopped immediately when trailer brake trigger squeezed.

So I guess there is an issue with my trailer....no surprise there as these things seem to be assembled from parts manufactured in China by 15 year old Elkhart, IN middle school dropouts....what a combo!

Originally Posted by markcee

Yeah, will definitely try the velcro but these results seem pretty consistent to me...my truck doesn't t brake my trailer, his truck does and vice versa....sight unseen, no tweaking, no nothing, plug and go. After my axle mishap I did drive almost 3K back home with no issue in braking.

I didn't try my truck today, but tried it for several miles after this problem was identified. Can't see how anything would change sitting in a parking spot for 3 days. The old school computer troubleshooter in me strongly indicates the issue being with my trailer wiring or brakes. Not trying to argue, but seems pretty conclusive from a rudimentary standpoint. What am I missing...and as always, thanks for input!

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.