How to Troubleshoot Turn Signals on Trailer Not Working
Question:
I had the kit I got from etrailer for my 1997 Toyota T100. Hooked up easy, but when I hooked to older boat trailer I only have tail lights. Blinkers work on truck but not trailer. Is the ground built in this kit when we fasten all fittings. I have ordered kit with leads from you to rewire trailer. What could be wrong?
asked by: Kyle B
Expert Reply:
The # 33355 trailer wiring harness you purchased receives its ground connection from its connection to the vehicle, it doesn't need a separate ground connection. The easiest way to test the harness would be to try plugging another trailer into the vehicle, then try another vehicle with the trailer. This will immediately tell you where the problem lies. If this isn't possible, I'll walk you through some troubleshooting strategies.
When you have trailer lights acting up, the first thing you'll want to do is test the trailer connector using a circuit tester like # PTW2993. Have a helper activate the turn signals as you test the sockets on the trailer connector. The socket fed by the yellow wire should light the tester up when the left turn signal is activated, or the brake pedal is pressed. The socket fed by the green wire should light the tester with the right turn signal and brake pedal.
If you don't get signal, check the connections where you plugged inline between the vehicle's wiring harness and the taillight assemblies. Make sure the connections are fully pushed together until they click. If you still get no signal with the tester, the wiring harness is faulty and should be replaced.
If you do get signal on the turn signal/brake lamp sockets, then the problem is in the trailer wiring or the lamps themselves. Since neither turn signal works, a ground problem is the most likely possibility. Make sure the trailer wiring harness is securely grounded to the trailer frame. The main ground us usually on the trailer tongue. Make sure the connection is tight and not corroded. The trailer lamps themselves should be grounded to the trailer either by a separate ground wire attached to the trailer frame or by the lamp mounting studs being directly mounted to the trailer frame. These connections also need to be tight and rust-free. If the trailer has a tilting or pivoting tongue, the connection at the pivot could be worn to the point where the ground connection is poor. Try using a short length of wire with two ring terminals on the ends to connect the tilting tongue to the rest of the trailer to make a continuous ground.
Run through the suggestions above. I'll also link to a trailer wiring troubleshooting article that you might find helpful. And don't forget to let us know how it works out!
Products Referenced in This Question
Product Page this Question was Asked From
Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Powered Converter
- Custom Fit
- 4 Flat
- Hopkins
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Does Trailer Lighting Ground Through the Hitch Ball
- Q&A: How To Wire Replacement 7-Way Connector On 2004 Chevrolet Suburban
- Q&A: Troubleshooting Tekonsha P3 Brake Controller Not Recognizing Trailer
- Q&A: Working Running Lights, But No Turn Signals or Brake Lights On Trailer
- Q&A: What is the Difference Between 7-Way RV and Utility Trailer Connectors
- Q&A: Troubleshooting 7-Way Installation that Has No Right Turn or Stop Lights on Trailer
- Shop: Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Shop: Hook Probe Circuit Tester
- Shop: Trailer Wiring
- Shop: Brake Controller
- Video: Hopkins Custom Fit Vehicle Wiring - Trailer Hitch Wiring - 33355 Review
- Video: Choosing the Right Trailer Wiring
- Shop: Trailer Hitch
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Search Results: brake controller
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Search Results: trailer brake controller
- Article: Trailer Wiring Diagrams
- Video: Choosing the Right Brake Controller
- Shop: Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Shop: Redarc Tow-Pro Liberty Brake Controller - Dash Knob - 1 to 2 Axles - Proportional
- Search Results: trailer hitch
- Article: How to Choose the Right Trailer Hitch Class
- Shop: Suspension Enhancement
- Search Results: hitch
- Shop: 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Video: Tekonsha Prodigy P3 Trailer Brake Controller Review
on Custom Fit Vehicle Wiring
