Archived Trailer Guys Questions
Boat Trailering Guys,
HI GUYS, MY TRAILER LIGHTS ARE NOT WORKING AT ALL. THEY HAVE WORKED FINE ALL SEASON (MAYBE REPLACE A BULB) BUT NOW THEY DO NOT WORK AT ALL. I HAD A "LOOSE" WIRE CONNECTION AT ONE OF THE LIGHTS AND REPAIRED BUT THEY STILL DON'T WORK. THE BULBS ARE FINE AND I AM GETTING POWER TO THE TRAILER 4-WIRE PLUG. WHAT IS MY BEST WAY TO TROUBLE SHOOT TO FIND OUT WHERE THE PROBLEM IS? OR DO I REPLACE THE WHOLE TRAILER HARNESS? THANKS, LISANTOM1
Answered on: 10/2008
We had a similar question in last month's Trailering Magazine. This was my suggestion: "Check your ground wires at the 4 wire adapter and at each light. 99% of my trailer light issues have been traced back to the ground wire and either a broken or corroded connection. Most installations do not run a continuous ground from the adapter back to the lights; they make the connection through the trailer frame. After many frustrating incidents of non-working lights I ran a ground wire from the adapter back to the lights and haven't had a problem since. I also carry a tester that plugs into the harness adapter at the vehicle that lights up if all wires are operating correctly. It eliminates one area of possible problem solving." Try this before replacing your entire harness.
Boat Trailering Guys: Mike