Troubleshooting Running Lights Not Working on Trailers Hooked Up to 2017 Ram 1500

Question:

I have a 2017 ram 1500 and when I hook up to any of my 3 trailers I only have brake lights and turn signals on all 3 so I know it’s not any of the trailers as two of them worked until recently and the third I just purchased. All other functions work such as the brakes just no running lights. Any ideas of this would be?

asked by: Kevin T

Helpful Expert Reply:

As you mentioned in your question we at least know this issue is coming from somewhere on the Ram, which is half the battle when troubleshooting a trailer light issue. The most common cause for just the running lights to not be working is a blown or missing fuse under the hood.

I was able to track down the online version of your Ram's owners manual and it looks like there's a 20 amp blue fuse in the F29 location and a 30 amp pink fuse in the F30 location inside the under-hood power distribution center that are in charge of the trailer running light circuit. Check these locations and make sure these fuses are in good condition, replacing if needed.

Most likely replacing one or both of these fuses will resolve the issue. If not it's really just a matter of inspecting any factory trailer wiring you can access on the truck for exposed/damages sections that need to be repaired. This can be pretty difficult so you may need to bring the truck up to a local Ram dealer to have them take a look.

expert reply by: Chris R