Possible Trailer Brake Issue
Hi folks,
backstory first:
End of August- self-installed the OEM integrated trailer brake controller/module. trailer brakes worked fine WITHOUT the ECU flash, just couldn't see what my gain was set to or change settings.
Middle of September- brought truck in for the tail gate recall, and had them flash/update the ECU while it was there to give me the trailer brake settings screens.
Day after the ECU flash- towing a trailer to move my dad's new tractor 15 miles or so, and the dash kept cycling through "check trailer brake wiring" warning, "trailer brake disconnected" warning, then back to "normal" operation. over and over again.
I stopped and checked connections, no luck. Restarted vehicle, nothing changed. That friday i had the day off so i threw in my 7-pin socket tester as well as used a multi-meter, and only get 1v off the brake pin whether or not the brake pedal is down/ manual lever is pushed, with either "light" or "heavy" trailer selected. tested the plug in the back of the socket too, no luck. checked fuses, they looked good (i think i checked all the right ones)
thought maybe the controller was defective, so swapped it under parts warranty and no change.
i've been reading that the OEM module might not output voltage unless you're moving? if that's true then maybe it's my trailer and not the truck wiring? I don't have another vehicle to test the trailer with, but it's just a (new) carry-on brand from tractor supply. basically at this point i'm just stumped. anyone have advice on the this?
backstory first:
End of August- self-installed the OEM integrated trailer brake controller/module. trailer brakes worked fine WITHOUT the ECU flash, just couldn't see what my gain was set to or change settings.
Middle of September- brought truck in for the tail gate recall, and had them flash/update the ECU while it was there to give me the trailer brake settings screens.
Day after the ECU flash- towing a trailer to move my dad's new tractor 15 miles or so, and the dash kept cycling through "check trailer brake wiring" warning, "trailer brake disconnected" warning, then back to "normal" operation. over and over again.
I stopped and checked connections, no luck. Restarted vehicle, nothing changed. That friday i had the day off so i threw in my 7-pin socket tester as well as used a multi-meter, and only get 1v off the brake pin whether or not the brake pedal is down/ manual lever is pushed, with either "light" or "heavy" trailer selected. tested the plug in the back of the socket too, no luck. checked fuses, they looked good (i think i checked all the right ones)
thought maybe the controller was defective, so swapped it under parts warranty and no change.
i've been reading that the OEM module might not output voltage unless you're moving? if that's true then maybe it's my trailer and not the truck wiring? I don't have another vehicle to test the trailer with, but it's just a (new) carry-on brand from tractor supply. basically at this point i'm just stumped. anyone have advice on the this?
I haven't seen many Carry-On trailers from Tractor Supply that actually have trailer brakes and a 7-pin connector. The one's I've seen at the store have the 4-pin but it looks like they do sell tandem axle enclosed trailers with brakes. Are you sure the trailer you were using has trailer brakes? I can't recall ever towing a trailer with my Ram that doesn't have trailer brakes so I'm not sure how it would react with the 4-pin connector connected.
On my 2014 Ram with the factory trailer brake controller the brake gain seems to work very much like the Tekonsha P3 I had in my previous vehicle. It appears to rely on accelerometers to adjust the gain based on how aggressive the stop and whether or not the vehicle is moving. I have my instrument cluster set to display the trailer brake gain during use and can see the gain vary depending on the conditions. So I would not be surprised if the brake voltage is very low when the vehicle is stationary.
On my 2014 Ram with the factory trailer brake controller the brake gain seems to work very much like the Tekonsha P3 I had in my previous vehicle. It appears to rely on accelerometers to adjust the gain based on how aggressive the stop and whether or not the vehicle is moving. I have my instrument cluster set to display the trailer brake gain during use and can see the gain vary depending on the conditions. So I would not be surprised if the brake voltage is very low when the vehicle is stationary.
Thanks for the reply. It definitely has trailer brakes. It’s an open utility trailer, 14’ deck, with tandem axles. Both axles have brakes.
Im going to go back to the trailer and hook up now that the new OEM controller is in, and try it out with the “heavy” trailer setting as I’ve heard that might help. Then I’ll start re-checking grounds on the trailer itself.
Im going to go back to the trailer and hook up now that the new OEM controller is in, and try it out with the “heavy” trailer setting as I’ve heard that might help. Then I’ll start re-checking grounds on the trailer itself.
off topic, im sorry, but how long did the tailgate recall take to perform? im scheduled to take mine in for that next week and wondering how much time i should expect to be sitting waiting.
I was in and out in a day, probably faster but I work far so couldn’t pick it up until that evening. I think they took it in a 8 and called me around 1.
On the brakes...Realizing that my output voltage is probably only low because the truck is stationary, I’m leaning toward a short in the trailer now. The problem is intermittent. When I hook up everything looks good, brakes hold the rig with the manual lever. When I’m driving I get intermittent cycles of normal operation, “check trailer wiring” warnings, and “trailer brakes disconnected” warnings.
The trailer is new but not under warranty (didn’t read the fine print of the ten-day registration requirement).
On the brakes...Realizing that my output voltage is probably only low because the truck is stationary, I’m leaning toward a short in the trailer now. The problem is intermittent. When I hook up everything looks good, brakes hold the rig with the manual lever. When I’m driving I get intermittent cycles of normal operation, “check trailer wiring” warnings, and “trailer brakes disconnected” warnings.
The trailer is new but not under warranty (didn’t read the fine print of the ten-day registration requirement).
Since you mentioned a short in the trailer, that jogged my memory. Several years ago I purchased a brand new camper and after only a couple of trips out I started having errors on my Draw-Tite brake controller. After determining that the brake controller was not the issue I started digging in to the trailer brakes. What I found was when the axle was assembled one of the wire retention clips was incorrectly installed and was pinching the brake wiring near one of the brake magnets. After very little use the retention clip sliced through the wire insulation and was causing a short of the brake wire to ground. I slid some shrink sleeving over the damaged insulation and installed the retention clip corrected and never had another problem with the trailer brakes.
-Rod
-Rod
Thanks rod, I’ll definitely take a look at that. I plan to narrow down by disconnecting one axle at a time and taking a quick drive, to see if I can narrow it down to one specific axle at least.










