Trailer Taillights Not Functioning, Reading 3.5 Volts at Trailer Connector
Question:
IHi, my trailer tail lights are not working but brake/signal do work. I measure only 3.5 volts at the truck 7 pin connector tail light pin. Ground pin measures ok. Would you have any ideas what would cause the voltage ? Thanks
asked by: Colin
Helpful Expert Reply:
The typical culprit would be a dirty or damaged trailer connector. Especially if the truck is more than a few years old. Take a look at the pins in the connector. If you see any white or green corrosion on the pins, there is the potential that the corrosion has spread to the interior of the connector and is interfering with the signal from passing through the connector. The # HM40975 would make an excellent replacement.
Products Referenced in This Question
7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- No Converter
- Custom Fit
- 7 Round - Blade
- 4 Flat
- Hopkins
more information >
Product Page this Question was Asked From
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Trailer Wiring
- Article: Trailer Wiring Diagrams
- Q&A: Trailer Running Lights Do Not Work but Brake Lights and Turn Signals Do Work
- Article: How to Troubleshoot Your RV Air Conditioner
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: Brake Controller Installation: Starting from Scratch
- Article: Testing Trailer Brake Magnets for Proper Function
- Q&A: How to Test Brake Controller without Trailer Connected
- Article: Troubleshooting 4 and 5-Way Wiring Installations
- Q&A: How to Make an Adapter to Go from Semi Truck 7-Way Round to RV Style 7-Way Blade on Trailer
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Q&A: Trailer Turn Signals Both Blink when Just Left Turn Signal is Activated
- Q&A: Troubleshooting No Running Lights on Trailer but Turn Signals and Brake Lights Work
- Q&A: Will The Curt Dinghy Wire Harness # C96JR Interfere With Activation Of A Blue Ox Patriot
- Q&A: Checking Trailer Lights Without Hooking Up to Vehicle?