Troubleshooting Trailer Running Lights Not Working with 2017 Ram 2500

Updated 08/19/2024 | Published 04/19/2018

Question:

I have a Dodge 2017 2500 diesel my problem is with the running lights on the trailer Im looking for the fuse in the truck I cannot find the location for the fuse the running lights on the truck work but not on the trailer

asked by: Jessika H

Expert Reply:

The trailer running light fuse according to your owners manual is F29 and is a 20 amp blue fuse. You will also want to check the trailer tow receptacle fuse F30 which is a 30 amp pink fuse. If these fuses are good, then I recommend checking each trailer wire pin at your bumper using a circuit tester like # PTW2993 to check for function. If you wiring on your truck is good, then you will need to connect your trailer and check the wiring there starting with the ground connection to the frame for a bare metal to metal connection.

If your vehicle wiring does not allow all the functions, then first try cleaning the pins with sand paper. If that doesn't work, then you will need to probe the wire insulation every few feet to find a wire short.

expert reply by: Jason S

Scott C.

6/17/2020

We have a 2015 2500 Promaster with factory tow package. We are not getting power to the 4 or 7 pin. I have disconnected the harness at the receptacle and tested. I got nothing. I pulled the wires and inspected them back to the trailer light computer module input. I seen nothing wrong. I used a test light at the input plug that also is the output for trailer lights. I have power going in, flashers, brakes and taillights and such all work. But nothing coming out. I have tried two new modules and results are the same, no power coming from module. Any suggestions?

Chris R.

6/21/2020

That's a tricky one. There has to be something going on with the factory wiring. I don't think it's a bad fuse since you ARE getting power at the input plug. Unfortunately with this type of issue your best resource will be with a local Ram dealer or the RV dealer since these are OEM components that are likely bad.

Corey E.

7/29/2021

I have a 3017 ram 2550 and I'm having issues as well, except I have no power at the fuses. I have power at the 30amp fuse but no others have power, no power at the rear plug, nothing....any thoughts?

Nick

11/21/2021

@CoreyE I had the same issue it was the BCM in the truck

See All (5) Replies to Scott C. ∨

Tracy H.

6/28/2020

One trailer parking light not working all other functions fine Help pls

Chris R.

7/2/2020

If the parking lights on just one side of the trailer aren't working my immediate reaction is a bad or weak ground. Make sure the light assemblies themselves are securely attached to a clean, bare metal surface (whether they ground through a dedicate wire or through their mounting hardware). Do the same for the main trailer harness. Let me know what you find and we can keep troubleshooting if needed.

Mike W.

7/13/2020

OMG!!! I have been searching the manual and trying different fuses for hours. Everything worked except the trailer tail lights (running lights). The manual has every fuse listed... "Trailer right signal".... "Trailer Left..." but does not list running lights. #29 was the ticket. It only shows as "Trailer Tow Parking Lights (If equipped)" in my manual. I replaced the 20 amp blue and everything works now. Thanks. (PS: Time for Dodge to make a tweak in their Owners Manual to be more specific on this one.). BTW I think I popped the fuse when testing the receiver. Musta bumped the tester against the positive and ground in the receiver. My Bad. M\

Chris R.

7/18/2020

I'm really glad we could help out with this!

Aaron

8/19/2024

@MikeW just had the same thing happen! Everything worked besides running lights. Found out the fuse wasn't even in after looking this thread up took my interior light fuse and used that 30a and worked! Fixed my issue! Amazing I can run my trailer at night now haha without worry of being stopped. Cause I've been carefully running at night around the 5-0 lol

James

7/20/2020

A couple of pictures would have been nice just sayin

Chris R.

7/24/2020

This isn't something we have a picture of. Pictures/diagrams of the fuse box will be in your owner's manual, as well as on the inside of the fuse box lid.

Mike C.

7/31/2020

Hi. I have a 2017 1500 dodge ram and when I hook up a trailer to my truck only the running lights work. I checked the fuses and they are good. I don't have brake lights or signals. Any idea what I can do? Thanks

Chris R.

8/10/2020

Have you tested the Ram's connector to make sure the truck is even the issue? Use a circuit tester on each of the pins while somebody flips through the light functions in the cab - see if they are showing power with them on. If they do, then the problem is actually on the trailer. If that's the case, inspect the trailer side connector for any debris or corrosion built up inside the pins and check the all the ground connections - both the main harness ground and those for the individual light assemblies on the trailer. Let me know what you find and we can keep troubleshooting if needed.

Mike C.

8/10/2020

@ChrisR thanks for your input! I did all that and it is definitely the truck. I also changed the two fuses. Still the same problem.

Jon G.

8/24/2020

@MikeC If your fuses look good and the issue is on the truck then you're going to have to trace the OEM wiring for the truck 7-Way for any damage as well as clean out any debris or corrosion that has built up in the 7-Way socket or any other connection points for the wiring. If that still doesn't fix the problem then you're either going to have to take it in and have a shop fix it or you're going to have to completely bypass your OEM trailer wiring.