Odd Voltage Readings and Malfunctioning Trailer Lights w/Curt Harness Installed on 2004 Lexus RX330
Products Featured in This Question
Question:
2 year old Curt powered tail light converter installed on Lexus RX330. Boat trailer lights worked fine until recently. Now tail lights work but turn/brake lights do not work. Tested trailer on other vehicle and everything works correctly. Multimeter showing 18v on tail light pin but only 2 volts on yellow and green wires. Any ideas? What would cause 18v reading?
asked by: Eric N
Expert Reply:
It sounds like the converter box may have shorted out, which can cause high and low voltage readings. To verify this, you will want to test the power going into and out of the converter box. If all power readings are fine going into the box but not coming out of the converter, then we'll know it is a problem with the box and not an issue with your Lexus. I've provided a link to our article on troubleshooting 4 & 5-way wiring installations which may be helpful.
It is most likely a short on the trailer's wiring that is responsible for shorting out the converter, so you should inspect the trailer wiring to look for the short before installing a new harness like # C55563. I've attached a video that will show how to find and fix wiring shorts. If you decide to replace your trailer wiring, I would recommend going with the Hopkins Endurance Trailer Wiring Harness, # HM48240. We used this kit recently to replace wiring on our trailer and I love the ergonomic grip on the connector which makes disconnecting much easier.
If you have additional questions, I am happy to help.
Product Page this Question was Asked From
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Powered Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Video: Beginner’s Guide to Installing the etrailer Trailer Hitch Receiver on a 2014 Lexus RX 350
- Shop: Trailer Hitch
- Shop: Brake Controller
- Search Results: 2" receiver hitch
- Q&A: What Should the Voltage Output Be at the 4-Way Plug on Curt T-Connector Wiring Harness # 56016
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Trailer Wiring
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Search Results: trailer hitch
- Video: Finding the Right Trailer Wiring Harness
- Article: How to Choose the Right Trailer Hitch Class
- Shop: Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Search Results: trailer wiring
- Article: My Trailer Hitch Doesn't Fit
- Shop: Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Q&A: What Is An OEM Prep Package And How Do I Know If I Have It
- Search Results: trailer hitch ball mount
- Video: Mounting Bracket 4-Pole Flat: The Breakdown
- Article: Best Bike Racks for Electric Bikes
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: Fifth Wheel Hitch
- Search Results: hitch bike racks
- Article: Trailer Wiring Diagrams
- Shop: etrailer Hitch Pin Alignment Collar for Hitch Accessories - 2" Hitches
- Q&A: Complete Towing Setup With Brake Controller for 2025 Honda Odyssey
- Shop: Roof Rack
- Search Results: hitch
- Video: Feature Breakdown: Universal Installation Kit for Trailer Brake Controller
on Custom Fit Vehicle Wiring
