Troubleshooting Trailer Running Lights that Dont Function
Question:
I bought some of your LED Trailer Lights. I have turn signal and brake lights but no running lights. My previous lights did not have a ground wire. Could the running lights not working be tied to not having a good ground to the trailer on the new lights?
asked by: Brian K
Expert Reply:
Nearly all trailer light issues end up being related to a bad ground so yes, it is very possible that your running lights aren't working because they don't have a sufficient ground. You can try running the ground of the assemblies back to the main ground wire of the trailer to see if that fixes the problem.
One thing you could do at this point is test the 4-way of the wiring harness with a circuit tester part # PTW2993 for voltage on all of the right pins when the taillight signals are being applied. Just like in the video I attached.
If the voltage checks out there but the trailer lights still don't function right then the problem is on the trailer wiring. That would mean that problem is either due to a ground issue or a short issue.
Make sure that the trailer side connector are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.
If the problem is on the vehicle side then I would first recommend you double check how the harness is installed on your vehicle, make sure all of the connections are good and tight. You should check all towing related fuses and relays as well. What you described can sometimes be due to the converter box shorting out.
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Products Referenced in This Question
Product Page this Question was Asked From
Miro-Flex LED Trailer Tail Light - Stop, Tail, Turn - Submersible - 12 Diodes - Oval - Red Lens
- Trailer Lights
- Tail Lights
- Stop/Turn/Tail
- Oval
- Recessed Mount
- Submersible Lights
- LED Light
- 6-1/2L x 2-5/16W Inch
- Red
- Optronics
more information >
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