Trailer brake not connected

[Sandbox]

I’ve been towing a friends 16’ enclosed trailer for the last two weeks during our move. During one drive, the instrument cluster started chiming in with “trailer brake not connected” and then would switch back to “connected”. It eventually just stayed with not connected. I originally thought it was a trailer issue but, with out the trailer connected the truck still shows the “trailer not connected” warning on the dash. This leads me to believe it’s an issue on the truck. Anyone else experience this?


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[Thendrix]

That sounds like a ground issue maybe? That's where I'd start anyway. Check for loose, broken, or corroded ground wires. I'm assuming the lights and brakes don't work when you get this warning?

 

[Sandbox]

Trailer Lights all work fine. Trailer Brakes work only if I manually engage the controller. They do not work when I push the brake peddle. Like I said, without any trailer connected, I still have the “not connected” message.


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[crash68]

The "Trailer not Connected" message will stay on the dash when you disconnect the trailer until you shut the truck off. If it's happening without a trailer ever being connected there's a problem with the brake controller.
A buddy had a similar issue where the trailer wouldn't register with the truck, turns out, one of his magnets was bad.

 

[SYKRAMMAN]

I’d have the controller itself checked.

Again I type too dam slow lol.

 

[Sandbox]

I knew it would stay on if the trailer was disconnected while the truck was running. I’ve done that many times. Restarting the truck would clear the message. But the trailer has been disconnected for a week and the truck started many times. I didn’t catch it at first because I’ve been driving my wife’s car and she has had the truck since she is home this week and she failed to mention that the error message was still there until this morning. Oh well, it’s still under warrranty so, Dealership here I come.


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[SYKRAMMAN]

I knew it would stay on if the trailer was disconnected while the truck was running. I’ve done that many times. Restarting the truck would clear the message. But the trailer has been disconnected for a week and the truck started many times. I didn’t catch it at first because I’ve been driving my wife’s car and she has had the truck since she is home this week and she failed to mention that the error message was still there until this morning. Oh well, it’s still under warrranty so, Dealership here I come.


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I definitely hear ya on the wife not saying anything when she sees or hears something part.

 

[Sandbox]

Found the problem. Issue was actually in the trailer 7-pin connector. The connector wasn't put together very well and allowed for some extra strain on the wires. I pulled it apart and found that 3 of the wires had broken at the terminal. I stripped them back and reconnected them and added an extra piece of wire loom so that the clamp on the 7-pin connector could actually clamp onto something. All is good now!

 

[VernDiesel]

Oddly I had that happen to mine, with multiple trailers, we changed the fuse and it stopped and never came back.

 

[glhefkin]

If my dash intermittently (after an average x miles driven) shares the message "Light Electric Trailer Brake Disconnected", accompanied by "Service Trailer Brake System", and I agree, since there is no trailer connected, I should suspect my trailer brake controller? Recently it started showing "SERV 4WD", accompanied by "Service Four Wheel Drive System", which is screaming electrical system. Something loose? Fuse connections> Wiring bundle connections?

 

[Daren Barry]

Oddly I had that happen to mine, with multiple trailers, we changed the fuse and it stopped and never came back.

If you don't mind me asking, what fuse did you replace? And where was it? I'm having this same issue… With the trailer disconnected error message showing up

 

[crash68]

If you don't mind me asking, what fuse did you replace? And where was it? I'm having this same issue… With the trailer disconnected error message showing up

This should be the all the fuses for the trailer plug wiring and the ITBM:
F53 ATR 20 amp Left Trailer lights
F81 ATR 20 amp Right Trailer lights
F29 FFM 20 amp Trailer Park lights
F28 FFM 20 amp Trailer Back up lights
F30 FFM 30 amp Direct from battery
F11 J Case 30 amp Brake Lever
F87 ATR 10 amp ITBM module

 

[2003F350]

Glad to see OP found the problem.

Every time I've seen this light on any truck, the issue has been at the plug. Generally, wiggling it will get the light to go out for a while.

My permenant solution? I carry a few of the short bungie loops in my truck at all times. Whenever I hook up a trailer that uses the 7-way round, I put one of these around it. I have never had the warning come on since, on any truck.

 

[dgjackson40]

If my dash intermittently (after an average x miles driven) shares the message "Light Electric Trailer Brake Disconnected", accompanied by "Service Trailer Brake System", and I agree, since there is no trailer connected, I should suspect my trailer brake controller? Recently it started showing "SERV 4WD", accompanied by "Service Four Wheel Drive System", which is screaming electrical system. Something loose? Fuse connections> Wiring bundle connections?

oh man I am having same issues on my 2012 Ram 2500! I know this is old post but did you find issue?

 

[2003F350]

9 times out of 10 when I've had this issue (or really any electrical issue dealing with trailers), it was caused by the connection at the plug. Sometimes it has been broken/corroded wires, but more often than not, the connectors are just loose. My solution has been to carry those short ball-ended bungie cords, and plug in, check the lights/brakes, put a bungie around it, one more quick check, and everything is good.

I've even had to do it on work trucks/trailers, and several guys had been insisting things were actually bad. My solution surprised them all.

 

[turkeybird56]

Glad to see OP found the problem.

Every time I've seen this light on any truck, the issue has been at the plug. Generally, wiggling it will get the light to go out for a while.

My permenant solution? I carry a few of the short bungie loops in my truck at all times. Whenever I hook up a trailer that uses the 7-way round, I put one of these around it. I have never had the warning come on since, on any truck.

Can U post pic next time how U do yer bungees???

I have found on MY 19, that 7 way picky. I have been using the same 7-6 way plug for years, and lately been losing trailer running lights and/or blowing fuse (20 amp cartridge). I found that I went out and Bought a new connector which fit snug and got everything back to where it needs to be. The connectors are only so so quality and loosen up, all IMHO...

 

[sabre851]

If my dash intermittently (after an average x miles driven) shares the message "Light Electric Trailer Brake Disconnected", accompanied by "Service Trailer Brake System", and I agree, since there is no trailer connected, I should suspect my trailer brake controller? Recently it started showing "SERV 4WD", accompanied by "Service Four Wheel Drive System", which is screaming electrical system. Something loose? Fuse connections> Wiring bundle connections?

This is the exact same thing my 2012 RAM 1500 has done. Message "Light Electric Trailer Brake Disconnected" as well as "SERV 4WD" with "Service Four Wheel Drive System" Also "CF" on train;er brake controller. How did you fix your truck?

 

[Jaredmurse]

This is the exact same thing my 2012 RAM 1500 has done. Message "Light Electric Trailer Brake Disconnected" as well as "SERV 4WD" with "Service Four Wheel Drive System" Also "CF" on train;er brake controller. How did you fix your truck?

Try changing the stop light button that is attached to the steering column under the dash near the brake pedal. When ones foot is off the pedal, the pedal is normally pressing on the button, allowing the vehicle to shift out of park. I’m getting the same error messages and when I mess with the button they go away. Also, I’m able to shift out of park without putting my foot on the brakes. I’m going to replace the switch and I’ll let you know if the problem goes/stays away.

 

[Spanky1]

This should be the all the fuses for the trailer plug wiring and the ITBM:
F53 ATR 20 amp Left Trailer lights
F81 ATR 20 amp Right Trailer lights
F29 FFM 20 amp Trailer Park lights
F28 FFM 20 amp Trailer Back up lights
F30 FFM 30 amp Direct from battery
F11 J Case 30 amp Brake Lever
F87 ATR 10 amp ITBM module

My 2015 is doing the same thing now. All lights work but trailer showing not connected. I pulled the F30 and checked it with a meter and appears good. However, when I check the pins for that fuse in the fuse box my test light does not come on. If it comes straight from the battery it should light, correct?

 

[crash68]

If it comes straight from the battery it should light, correct?

The +12V pin on the 7 pin plug should stay hot all the time.
If your having a trailer disconnect issue, look for problems with the trailer bake circuit. People have had issues with the wiring harness that runs by the back of driver's side front wheel. You have to pull the wheel well liner down.