2025 trailer lights

[Rebel2022]

Been seeing a few issues with 2025’s not lighting trailer lights and now i’m having a few weird issues. I have 3 trailers, 20’ flat deck has all incandescent, no brakes and works fine. 14’ cargo all incandescent with trailer brakes and the driving/marker lights won’t light at all. Brakes, brake lights and signals are fine. Truck flashes warning trailer lights out. 30’ travel trailer, mostly incandescent with a couple leds. All lights work but truck flashes warning trailer lights out. Another weird thing, towing the cargo trailer the other day on a couple hundred km highway trip and noticed the battery volts dropped to 12.6-12.8 range (whole driving) never saw that happen before, always 13.8-14.2 unless start/stop. Then i get a service shifter warning and the light on the console shifter goes out. Then a 4wd system not available warning. Get home, unhook and then over the next day or so battery voltage slowly went back up to 13.8-14.2 as always.

Anyone have any thoughts?

 

[Rebel2022]

Guess no one else having issues. Messed around today with the cargo trailer. It has all incandescent bulbs, x2 tails, x4 front amber, x7 marker x2 fender and x1 license plate. Confirmed power to marker light blade on truck with lights on. Plugged in and turned lights on and they flashed for a second and shut off. Could not get it to do this again without unplugging and cycling the ignition. So I unplugged the tails and turned the lights on and they stayed on this time. Plugged tails back in and unplugged 4 markers and tried, lights flickered and shut down. Kept unplugging more marker lights and finally they stayed on with 2 tails, one license plate light and 4 markers. So the truck obviously has some kind of built it sensor telling it too much voltage with lots of bulbs and trips some kind of circuit. It must be set to low so we’ll see what the dealer says about it.

One more thing I can’t figure out. The battery blade on the truck plug does not output 12v at anytime, key on, key off, plug on plug out nothing. Looked for a fuse related to this in the truck, could not even find a fuse relating trailer/plugs.

 

[Marine6212]

Does the 2025's 12v blade run through the itergrated trailer brake controller?

"The battery blade on the truck plug does not output 12v at anytime, key on, key off, plug on plug out nothing. Looked for a fuse related to this in the truck, could not even find a fuse relating trailer/plugs."

 

[Rebel2022]

Does the 2025's 12v blade run through the itergrated trailer brake controller?

"The battery blade on the truck plug does not output 12v at anytime, key on, key off, plug on plug out nothing. Looked for a fuse related to this in the truck, could not even find a fuse relating trailer/plugs."

I have no idea?

 

[Richard320]

You asked for thoughts, so here goes.
1) Check the connection on the backside of the 7 pin recepticle. I recall reading about problems getting it to seat properly.
2) I think the charging line fuse is F01 on the interior fuse box, according to this video. There are also two fuses in the underhood fuse box labelled ITCM. I believe that stands for integrated trailer control module

 

[Rebel2022]

You asked for thoughts, so here goes.
1) Check the connection on the backside of the 7 pin recepticle. I recall reading about problems getting it to seat properly.
2) I think the charging line fuse is F01 on the interior fuse box, according to this video. There are also two fuses in the underhood fuse box labelled ITCM. I believe that stands for integrated trailer control module

Thank you for this, I will be checking.

 

[NY_Ram]

I also have issues with my trailer lights on my 2025 limited.
I have a 2 year old single axle PJ utility trailer with LED lights all around, 4 pin connector. Works 100% fine on my wife's Jeep.
On the RAM, if I have my headlight switch in Auto, during the day with the lights off and the trailer hooked up, it will complain to check the trailer wiring. Moving the headlight switch to either ON or OFF will clear the error most of the time. Strange thing is all the lights work fine. Hitting the hazard lights show the brake lights work and turning on the headlights will light up the markers and license plate, but the truck still complains. And i have never been able to get the trailer light test to do anything, ever. We towed the ATVs this past weekend and the error was gone all the way up and the truck complained all the way back. But, as far as i can tell the lights always work, pulled over twice to check. Annoying...

 

[mark92a]

I also have issues with my trailer lights on my 2025 limited.
I have a 2 year old single axle PJ utility trailer with LED lights all around, 4 pin connector. Works 100% fine on my wife's Jeep.
On the RAM, if I have my headlight switch in Auto, during the day with the lights off and the trailer hooked up, it will complain to check the trailer wiring. Moving the headlight switch to either ON or OFF will clear the error most of the time. Strange thing is all the lights work fine. Hitting the hazard lights show the brake lights work and turning on the headlights will light up the markers and license plate, but the truck still complains. And i have never been able to get the trailer light test to do anything, ever. We towed the ATVs this past weekend and the error was gone all the way up and the truck complained all the way back. But, as far as i can tell the lights always work, pulled over twice to check. Annoying...

Same on my 25 limited.

 

[DadRam]

been having same kind of issues with our TT. 2022 imagine. connection check and tail lamp check on screen while towing. stopped and check all lights are on and working. in research am finding finding others with issues on 2025 1500. looks like Ram lowered the capacity of the trailer plug. seems too much draw and the module errors out. going to try to change out TT lights with LED bulbs. seems to be typically engineering issue with no insight as to what they may be changing....
google. "2025 ram trailer lights optimized for led Ram 1500" some great discussions to follow on FB groups.

 

[Canojams]

If you have the hurricane engine the only fix is to convert to LEDs the computer only allows up to 3.45 amps draw onrunning lights. My trailer has 16 incandescent and draws,7.7 amps. Tail lights draw around 1/2 amp so cn only run 6 , you need 4 at a minimum, 2 tail,2 license so gou are screwed. Do not let the dealer say it is your trailer. You will get several codes and dash displays but none are what is happening. They charged me $199.00 diagnostic fee. This is their justification.