Troubleshooting Reverse Lights on Trailer that Stop When Running Lights Come On

Question:

I recently added reverse lights to my utility trailer and upgraded it to a five way flat harness. All of the lights work as they should except the reverse lights. They come on when the truck is shifted to reverse, but only if the marker/driving lights are off. If I turn on the marker lights the trailer reverse lights shut off. On the truck side I have the Hopkins 48470 Endurance. Is this normal with a five way?

asked by: Brandon

Expert Reply:

What you described is not normal for reverse light function but it is normal for insufficient grounding on the trailer. Try improving the main ground of the trailer wiring harness from the trailer frame to the connector and you should see the problem go away. This issue happens when there's just too much amperage that needs to be drawn and basically the ground can't keep up.

expert reply by: Jameson C