running lights on boat trailer

[billbo]

My running lights on my boat trailer are not working. The brake lights and turn signals work fine. I have checked all the wires and appears to be in good working order. Help me if you can.

[92 5 oh]

I just reread that.  are you using a 4 wire plug or more?  if its 4 wires, the brown wire is the one for the running lights. it sounds like that is where your problem is if all other lights are working ok except the running lights. you may have a poor connection in one of the connectors or even where the connector is sliced into the tow vehicle. i would start by seeing if the brown wire on the tow vehicles is getting power. if it's not, the problem is on the tow vehicle wiring. if it is getting power, then connect it to the trailer, probe the brown wire and see if you're getting power on the brown wire. if you are, keep moving down the wire until you get less than ~12v. it sounds like your ground is good if the brake lights and turn signals are working. but i've seen some wierd stuff happen when there is a bad ground. so definately check for good ground, specifically near the running lights. hope this helps. good luck!!

[luger306]

check your ground make sure it is grounded to the trailer

[tntitans21399]

Most likely it is the ground.  You have the ground wire from the trailer to the truck, but most of the time that isn't a good enough ground.  You pretty much get your ground from the trailer to the truck by the trailer ball itself.  That's why something you will see a trailers lights flicker when it hits a bump.  You can scrap off any rush that might be in the coupler on the trailer where the ball goes.  I have that problem with a 16ft open trailer of mine.  I usually make some real sharp turns and almost jack knife the trailer to get to knock off any dust or rush to get a good ground connection and I'm good after I do that.

[billbo]

Thanks for the suggestions. I will try to knock off some rust and see what happens. Catch a big for me!

[JayDub]

Special fuse in some truck models for trailer running lights.  Replace.

[BassChump]

It doesn't sound like a gound problem to me. If the ground was bad, the turn signal lights and brakes lights probably wouldn't be working as well. To me, it sounds like the hotwire going to the running lights.

The simplest way to check this is to buy a cheap 12 volt tester. The kind that has a probe and a light and a wire with a clip on the end. Get 'em almost anywhere for a couple of bucks. Take the clip and clip it to any metal. The bumper, the hitch, something substantial. Turn on the lights and the left blinker. I'll assume you have a flat 4 wire plug. There should be 4 colors of wire. If it's wired properly, green should be the right blinker, yellow the left blinker, white is the ground and brown is the running lights.

Put the probe in the socket that goes to the yellow wire and the light on the probe should blink on and off. If it does, you know your probe has a good ground. Now put the probe in the socket with the brown wire. It should have a steady light. If you don't get a light, then you'll need to follow that wire under your truck and find the break or bad connection.

 If you have a good light, then the problem is in the trailer wiring.

Plug the trailer into your truck and now you can check the running light wire going to the trailer.

Just a thought??? Have you checked the bulbs at all?? It's not all that uncommon for the bulbs to have gone bad.

Hope this helps.

[billbo]

I will be glad to give it a try. Thanks

[JShrock07]

Check the fuses in your truck, but I didn't read it yet but have you checked to bulbs? I had the same problem before and I didn't even think to check the bulbs. ;D ;D ;D

[Ann-Marie]

HOW I GOT RID OF ALL MY TRAILER WIRING PROBLEMS.

I made up a 2x4 beam that would lock onto the rear of the boat.  In my case the rudder was removable so I made pins that just dropped into the rudder bearings.  You can make something equivalent.

The all the lights and license plate were attached to the beam.  Before putting the boat in the water you lifted the lights off and put them in the back of the vehicle.  After loading you just put it back on.

NO ELECTRICAL WIRING ON THE TRAILER AT ALL.