Troubleshooting Voltage Drop When Connecting LED Trailer Lights to Wiring Harness

Updated 09/16/2024 | Published 05/08/2019

Products Featured in This Question

Load Resistor Kit for LED Turn Signals - 50 Watts - 6 Ohm - Qty 2

(42)

$10.76

Question:

I have 12 vdc on the brown line without the lights connected. as soon as i connect the wires, it s to 7 vdc and its not enough to light the LED. Why is it dropping voltage?

asked by: David S

Expert Reply:

It sounds like the ground connection often in the mounting hardware of your lights is not connected well. This ground needs to be bare metal to metal and free of all corrosion and debris. If with a clean ground you still are not getting the desired function, you will need to add more resistance to the light fixture by adding a load resistor like the LED Light Bulb Load-Resistor Kit # DI34ZR to draw the desired power for proper function.

expert reply by: Jason S

click to enlarge

Marvin

9/16/2024

Hello Jason, I experienced the voltage drop from 11.8 VDC to 5.9 VDC. After reading your post I checked ground to the trailer frame and changed it to a positive wire ground to each LED light. A lights are very bright !!! I appreciate you sharing the electrical information. Marvin Walden