Trailer Running Lamp Circuit of 2018 Chevy 2500 Not Working At Trailer Connector
Updated 06/18/2025 | Published 08/21/2021
Products Featured in This Question
Question:
My 2500 has the dual-terminal socket in the number 7-blade on top and 4-prong on bottom. I need both because I pull both a larger trailer and a small utility trailer. The tail lamp for both sockets no longer work and I get a warning on the dash that says ‘Check Trailer Wiring’. The dealer told me it was the trailer wiring but I tested both my trailers on other vehicles and had no issue. I also used a test light and there is no power to the tail lamp blade/prong for either. The turn signals, brake lights, reverse lights, all work. I’ve read of others having similar problems with this dual terminal setup. Do you have any recommendations? Thanks
asked by: Frank B
Expert Reply:
Lets begin with the non-functional trailer running lamp circuit. I'd suspect a fuse in the engine compartment fuse block in location # 15. Replace the fuse but before plugging the trailer back in, you'll want to closely examine the running lamp circuit on the trailer and its trailer connector to locate the short and repair it or you continually blow fuses. This could be an intermittent problem caused by a loose connection or some cracked or worn wire insulation on the wire in the running lamp circuit.
Because of the way the doors of the OEM socket are hinged, it isn't possible to open both the covers at the same time. The best way around this would be to install a T-harness like # C55384 which will plug in at the connection between the tow package harness and the trailer connector. This will allow you to use the 7-way as well as having access to a functional 4-pole at the same time.
I've linked to some trailer wiring and troubleshooting articles that you might find hepful.
(click to enlarge)
Product Page this Question was Asked From
Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- 7 Blade
- Plug Only
- Pollak
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Video: Review of TecNiq Trailer Lights - Tail Lights - TN84AR
- Shop: Trailer Wiring
- Search Results: trailer lights
- Search Results: 7 pin connector
- Search Results: 2" hitch bar
- Search Results: tag light
- Search Results: 3" reciever
- Video: Review of CURT Trailer Wiring - Dual Connection Socket Bracket 4 And 7 Way - C36GJ
- Shop: TecNiq Stop Tail Turn Reverse Light - 6" - Oval - Amp Plug - Grommet Mount
- Shop: TecNiq Stop Tail Turn Light - 6" - Oval - Pigtail - Grommet Mount
- Shop: Curt Dual Connection Socket w/ Bracket - 7-Way RV Style and 4-Way Flat - Vehicle End
- Shop: Pollak 7-Pole Round RV-Style Trailer Connector Socket - Vehicle End
- Q&A: Outside Dimensions of Draw-Tite 24-Inch-Long Combo Bar 2852
- Q&A: How to Use the Tekonsha Prodigy Brake Controller on a 2018 Volkswagen Atlas SEL
- Video: Optronics Mini LED Trailer License Plate Light w/ Chrome Housing Feature Review
- Video: Hands-On with the Combo Bar with 2" Trailer Hitch Receiver
- Video: Let’s Check Out the PVC Grommet for 6-1/2" Oval Trailer Tail Lights
- Shop: 7-Pole and 4-Pole Trailer Connector Sockets w/ Mounting Bracket and Wiring - Vehicle End
- Shop: Curt Solid Steel 3" Hitch Bar with Raw Finish - 18" Long
- Shop: Optronics Fleet LED Trailer Tail Lights w/ Grommets - Stop,Turn,Tail - Submersible - Oval - Qty 2
- Video: Review of B and B Molders RV Trim - Plastic Molding - BM65XR
- Q&A: Can a Fifth Wheel Hitch be Used With Weather Guard Toolbox on 2016 Ram 2500?
- Shop: Gooseneck Hitch
- Q&A: Choosing Between the Fixed and Slider B&W Companion 5th Wheel Hitch for a 2020 GMC Sierra 2500 SB
- Shop: Fifth Wheel Hitch
- Video: Review of B and B Molders RV Trim - Plastic Molding - BM55ZR
- Search Results: telesteps telescoping ladder
- Q&A: Where is Trailer Running Light Fuse of 2018 Chevy Silverado
- Q&A: Troubleshooting Trailer Running Lamp Circuit on 2020 Chevy 1500
- Shop: Nerf Bars - Running Boards
on Custom Fit Vehicle Wiring
Adam
5/25/2025
no power on the fuse terminals on the truck?