Troubleshooting Driver Side Taillight Not Working on 2020 Rockwood Mini Lite 2109S

Updated 08/30/2021 | Published 08/28/2021

Products Featured in This Question

Low Profile LED Combination RV Tail Light w/ Bracket - 4 Function - 8 Diodes - Round - Driver Side

(26)

$25.85

Hook Probe Circuit Tester

(61)

$13.33

Question:

Tow Vehicle: 2017 Toyota Tacoma Trailer: 2020 Rockwood Mini Lite 2109S My trailer tail lights are mostly functional except for my driver tail running light does not illuminate. Driver tail light works for braking and turn signal, Passenger tail light works for running, braking, and turn signal. This sounds like a wiring issue maybe ? or the fixture needs replacement. I don’t think this is a tow vehicle issue, as the Passenger tail running light works ok. What is the best way to check the wiring? Should I remove the tail light fixture and check the 3 wires for connection, or is there any other troubleshooting recommended? I guess this might be grounding ? but not sure how to troubleshoot more. To remove the tail light fixture, is this best accomplished by stripping the cover caulk around the cover rim, and then twisting the red lens cover?

asked by: Jerry D

Helpful Expert Reply:

I think you are correct, this sounds like a wiring connection issue. Given the fact that this is a 2020 trailer and the # RVSTL11 is an LED light, it is unlikely that the fixture needs to be replaced. Of course that doesn't mean it is impossible.

As you said, the brake and turn signal work, which comes from the red wire on the back. The black wire is for the taillights and your license plate cover light. If the black wire has a loose connection that would explain the partial functionality of your light. You would need to remove the caulk, remove the lens, and remove the screws from the 3 mounting holes in order to gain access to the connections for the light. Check the connection on the black wire, as well as the ground connection. If that does not fix it there are a few other things you can check.

Whether you have a 4-way or a 7-way the wire (typically brown) for the taillights/running lights powers both the passenger and driver side. Since your light on the passenger side is working properly you are correct again, it is unlikely that the tow vehicle is the problem. However, I would suggest checking the ground connection on the vehicle side just to be safe. If that still does not fix the problem, you may use a circuit tester like the # PTW2993 to test the connection and make sure it has the correct power reading.

If you find that you are still having the same problem, you could attempt to determine if the light needs to be replaced by removing the light on the passenger side. Then use the passenger side connections to see if the taillight functions work on your # RVSTL11.

I have attached a helpful article on troubleshooting wiring for your reference which includes steps to solve common wiring issues. If you find that you are still having a problem please reach out and I will help you troubleshoot further.