Trailer brake warning in tow vehicle. [RESOLVED]

jdfishing

Well-known member
I have a 2016 RAM and tow a Bighorn. Lately, I am receiving a message in the truck, "check Trailer brake wiring" or " trailer disconnected". The messages appear very intermittently, but always while towing. The cable to the truck has been replaced. I checked all of the connections I could and have not been able to find the problem. Any suggestions?
 

CoveredWagon

Well-known member
Re: Trailer brake warning in tow vehicle.

I have a 2016 RAM and tow a Bighorn. Lately, I am receiving a message in the truck, "check Trailer brake wiring" or " trailer disconnected". The messages appear very intermittently, but always while towing. The cable to the truck has been replaced. I checked all of the connections I could and have not been able to find the problem. Any suggestions?

Check the male connector socket on the truck. Wires could be poorly connected or the pins could be corroded or damaged.
 

JohnDar

Prolifically Gabby Member
Re: Trailer brake warning in tow vehicle.

I lost trailer brakes once while towing. Used some spray electrical contact cleaner on the receptacle and the plug and it was fine after that. Doesn't take a lot of oxidation on the contacts to interfere.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

I lost trailer brakes once while towing. Used some spray electrical contact cleaner on the receptacle and the plug and it was fine after that. Doesn't take a lot of oxidation on the contacts to interfere.

Thanks for the suggestion. They looked clean, but I know electrical can be temperamental.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

Could also be a broken wire a at one of the brake magnets

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Thanks Jarrod. I presume you have to pull the wheel to check? The thing that throws me is it is very sporadic. I can get the warning five times in a minute and then drive an hour and it's fine. Also, it only happens while moving.
 

Jesstruckn/Jesstalkn

Well-known member
Re: Trailer brake warning in tow vehicle.

John how long has it been doing this ?
Was it doing it before I put my box on ??


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Re: Trailer brake warning in tow vehicle.

Started having the exact same issue on our last trip home. Can't recreate it in the driveway...yet.
Appreciate all the suggestions above and will try each out.
 

Bones

Well-known member
Re: Trailer brake warning in tow vehicle.

Please check the wires going through the axles for shorts. if it shorts directly to ground your truck thinks there are no brakes.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

John how long has it been doing this ?
Was it doing it before I put my box on ??


Sent from my XT1585 using Tapatalk

Yes, it was doing it before the box. It started all of a sudden on our way to the Wash rally.

- - - Updated - - -

Please check the wires going through the axles for shorts. if it shorts directly to ground your truck thinks there are no brakes.


Thanks, I'll recheck that. I did wiggle and play with those wires, trying to get it to trigger the warning, but no luck.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

Started having the exact same issue on our last trip home. Can't recreate it in the driveway...yet.
Appreciate all the suggestions above and will try each out.

If you get it figured out before me, please share. I'm baffled.
 

Bones

Well-known member
Re: Trailer brake warning in tow vehicle.

Yes, it was doing it before the box. It started all of a sudden on our way to the Wash rally.

- - - Updated - - -




Thanks, I'll recheck that. I did wiggle and play with those wires, trying to get it to trigger the warning, but no luck.

My issue was deep inside the axle. you would never see it until you pulled the wires out.

IMG_20150716_180754.jpgIMG_20150716_180733.jpgIMG_20150517_170207.jpg
 

pegmikef

Well-known member
Re: Trailer brake warning in tow vehicle.

Thanks Jarrod. I presume you have to pull the wheel to check? The thing that throws me is it is very sporadic. I can get the warning five times in a minute and then drive an hour and it's fine. Also, it only happens while moving.

I had a similar issue with my F350 and the culprit was that my connector plug was making intermittent contact with pin seven (brakes) causing the message and the brakes to fail. It apparently also caused periodic locking of my brakes while towing which ruined a pair of g614s. I have disc brakes. The tech thoroughly cleaned and scraped all the contacts in the connector and the plug, shot them with brake cleaner, and checked every thing else. No problems since.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

Still have the brake disconnected problem and it has gotten worse. The 5th wheel is parked in the driveway and when I hook it up to the truck, I get the warning message. Now, if I can just find a mobile tech to come and check it out. One won't even return my phone call. Guess business is really good.
 

Jesstruckn/Jesstalkn

Well-known member
Re: Trailer brake warning in tow vehicle.

John
Maybe theres something I can do when we get home from Temecula at the end of the month.

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Lou_and_Bette

Well-known member
Re: Trailer brake warning in tow vehicle.

John, try something for me, go to your truck, turn the key on but don't start. Step on the brake and have someone look to see if the "cyclops" (extra stop light). I had a problem similar to yours on my 2008 F450. Couldn't find a cause and took it in for fluid change. Later, tech called and ask if I knew that my "cyclops" light was out, and for how long? Told him I didn't know that light was out but did know that I was having problem with getting intermittent "trailer disconnected." He thanked me for that bit of info because he hadn't been able to find reason light wouldn't work until I told him about the trailer disconnect which led him to a relay, not fuse but relay. He replaced the relay and both problems went away.
 

Domi

Well-known member
Re: Trailer brake warning in tow vehicle.

I will second the problem with the wires going into the axels. I had that exact same problem about 6 months ago. It would come in and out.

One way to check if you have electric breaks is while parked have someone step on the break pedal and then go and listen to see if you can hear the hum at each wheel. You can also use a compass to see if the magnets are engaging. That will tell you what wheel to look at.

You can use a multimeter from there to see if a wire is shorted to the frame.

In my case I had the bottom down for work on the fresh water tank and when I put it up I left to much slack in the break wires and they rubbed against the leaf springs and eventually shorted to the frame. It took actually feeling the wires that were exposed to find where the insulation had rubbed off. Going down the road sometimes they were okay other times they were shorted and the brake controller would say the trailer was disconnected. It was a real pain getting it stopped when a stoplight changed quickly on us.

Good luck, hope you find an easy solution.

John
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

John, try something for me, go to your truck, turn the key on but don't start. Step on the brake and have someone look to see if the "cyclops" (extra stop light). I had a problem similar to yours on my 2008 F450. Couldn't find a cause and took it in for fluid change. Later, tech called and ask if I knew that my "cyclops" light was out, and for how long? Told him I didn't know that light was out but did know that I was having problem with getting intermittent "trailer disconnected." He thanked me for that bit of info because he hadn't been able to find reason light wouldn't work until I told him about the trailer disconnect which led him to a relay, not fuse but relay. He replaced the relay and both problems went away.

Thanks Lou. I'll check it. Sorry for the delay.
 

jdfishing

Well-known member
Re: Trailer brake warning in tow vehicle.

John
Maybe theres something I can do when we get home from Temecula at the end of the month.

Sent from my XT1585 using Tapatalk

Thanks Jarrod. We are headed to the coast on Monday for two weeks. I have a tech scheduled in Dec to come look at it. Hopefully he can find it. Thanks for the offer and sorry I'm so late with this. The forum is kinda at the end of my list of social sites to visit and I didn't think there would be anymore responses. I'll let you know the outcome.

- - - Updated - - -

I will second the problem with the wires going into the axels. I had that exact same problem about 6 months ago. It would come in and out.

One way to check if you have electric breaks is while parked have someone step on the break pedal and then go and listen to see if you can hear the hum at each wheel. You can also use a compass to see if the magnets are engaging. That will tell you what wheel to look at.

You can use a multimeter from there to see if a wire is shorted to the frame.

In my case I had the bottom down for work on the fresh water tank and when I put it up I left to much slack in the break wires and they rubbed against the leaf springs and eventually shorted to the frame. It took actually feeling the wires that were exposed to find where the insulation had rubbed off. Going down the road sometimes they were okay other times they were shorted and the brake controller would say the trailer was disconnected. It was a real pain getting it stopped when a stoplight changed quickly on us.

Good luck, hope you find an easy solution.

John

Thanks Domi. I like the compass thing on the wheel. I'll try that.
 
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