Trailer Brakes Disconnected message

Every time i hear this about a newer RAM it's the trailer NOT the truck!

ktmrfs wrote:
Vehicles from all 3 mfg seem to have the problem show up occasionally. The GM system looks for a given resistance on the brake control wire to determine if the trailer brake system is connected. Once it thinks it is, it continues to monitor and if it goes out of range then the warning comes up. I suspect this is similar on others as well.

GM has had a few TSB's on the issue. What I have found it to make sure the connector on the TV and trailer is well seated, and clean. And that the TV connector doesn't have any moisture in it.

Also some of the lesser brands of trailer plugs have pretty weak spring force on the contacts, doesn't help.

Older controllers that monitored the connection would allow a small voltage to be present on the output. Not enough for the brakes to grab but just enough to see a small current being drawn by the magnets.

Newer modern controllers use a timed pulse to see if there is a ring or echo back. No ring or echo, no connection. Timing and size of the echo can also be used to determine connection and poor or bad wiring can affect the detection.. Basically if your wiring is not good, the controller will alert you with a disconnect or random disconnect/reconnects messages..

Interesting. We had this last year while on a trip with our F350 and FW. Took the truck to the dealership to check. There was a problem with older F350 pin connectors, but not this one. Thoroughly checked and not the truck. Pin connector end looked worn (pigtail), so replaced that. Still the problem. Pulled trailer back and forth and brakes "were" working. Last ditch effort, took it to a local Les Schwab and lo and behold, the brake wires were worn through on one side, magnets not connecting as a result. Replaced, inspected other side and all good to go! Scary thing is that we got this intermittent message earlier in the year on two different mountain trips. I told hubby that when he pulled the FW forward I could hear clunking on one side. Good luck in tracking it down.

Thanks for all the replies. At this point I don't think its the truck but trying to figure out what it is on the trailer. May even try another similar truck and see if the same issue appears just to be sure.
The connections all look good with no corrosion. First time i've experienced this issue before.

Keep us posted!!

wvu_traveler wrote:
Thanks for all the replies. At this point I don't think its the truck but trying to figure out what it is on the trailer. May even try another similar truck and see if the same issue appears just to be sure.
The connections all look good with no corrosion. First time i've experienced this issue before.

The rub is the connections can "look good" but in reality are bad.

Typically non weather proof crimps are used to make the connections which allows moisture in the air and water splash to find its way into the crimp and wick into the wire. That moisture over time corrodes the wire creating high resistance. I would at a minimum cut the crimps, resplice the connections with outdoor rated connectors.

Additionally, axle manufacturers run the wire through the hollow axle tubes. The wire inside is free to move about which can lead to the wire breaking inside the tube or scuffing the insulation from the wire and creating random shorts.

The fix there is to bypass and run the wire on top of the axles (lots of wire ties) or run the wire back to the trailer frame and across to the other side.

Gdetrailer wrote:

wvu_traveler wrote:
Thanks for all the replies. At this point I don't think its the truck but trying to figure out what it is on the trailer. May even try another similar truck and see if the same issue appears just to be sure.
The connections all look good with no corrosion. First time i've experienced this issue before.

The rub is the connections can "look good" but in reality are bad.

Typically non weather proof crimps are used to make the connections which allows moisture in the air and water splash to find its way into the crimp and wick into the wire. That moisture over time corrodes the wire creating high resistance. I would at a minimum cut the crimps, resplice the connections with outdoor rated connectors.

Additionally, axle manufacturers run the wire through the hollow axle tubes. The wire inside is free to move about which can lead to the wire breaking inside the tube or scuffing the insulation from the wire and creating random shorts.

The fix there is to bypass and run the wire on top of the axles (lots of wire ties) or run the wire back to the trailer frame and across to the other side.

Our problem was in the actual wheel hub. Once they pulled it, they found the problem.

ReneeG wrote:

Our problem was in the actual wheel hub. Once they pulled it, they found the problem.

Yes, that is correct as there are pinch points where the magnet wires can get caught and insulation damaged or the wire breaks.

But generally only one out of four magnets being disconnected isn't going to generally cause the controller to point out a failure unless the wire is touching and shorting to the metal or shorting both magnet wires together inside the drum..

Controller doesn't care if there is one or six magnets as long as it gets the ring back from the pulse as expected. Typically you will have two to six magnets depending on axle count so controller has to be a bit flexible.

Logically since this problem is showing up on RAM and Ford trucks and we all have different RV's thus the problem is most likely in the truck connections and/or plug. Especially since it goes away for a time after cleaning the connectors.

agesilaus wrote:
Logically since this problem is showing up on RAM and Ford trucks and we all have different RV's thus the problem is most likely in the truck connections and/or plug. Especially since it goes away for a time after cleaning the connectors.

Ford and RAM controllers may be a bit more "sensitive" to wiring faults on the trailer which would explain the reason they appear to show a fault more readily. I know when Ford first brought out their own TBC there where lots of complaints about random disconnect events posted here and other forums. That has diminished over time.

The fault is generally found with the trailer side of things as trailer manufacturers use the lowest quality materials they can get away with. This means they typically use the lightest, cheapest pigtail (smaller ga wires) and connector as possible (single sided prongs), the lightest wire gauge possible (mine was 16 ga) and non weather proof crimps on the connections.

As a preemptive measure I replaced the light duty pigtail with a heavy duty pigtail which has double sided prongs in the molded on plug. Additionally, I ran all new 10 ga wire (x2 runs) back to the axles (replacing the factory 16 ga wire which had multiple factory splices). Bypassed (disconnected the internal wire in the axle tubes and ran the wire across the trailer frame)the internal light ga wire running though the axle tubes with external heavier ga wire and weather proof splice connectors.

The result has been zero disconnect messages with a 2013, 2019 and 2020 F250..