Boat trailer lights

On my boat trailer all the lights work except the right brake light and right blinker everything else works. I have changed out the trailer plug with a new one and everything seems to be working from my truck could it be a broken wire in my trailer

Re: Boat trailer lights

Welcome to iboats.


Have you checked the bulb itself?

Do you have power in the wire near the light?

Does the right running/tail light work?

If not, check the ground wire for that light. Make sure it is making good contact with the frame.

Re: Boat trailer lights

It is a sealed bulb and yes the tail light works. I just bought the lights last week. I have even swapped the two lights still the same thing it's got to have power to the light for the tail light to work any other suggestions would be greatly appreciated

Re: Boat trailer lights

Not seeing any pictures or knowing what type lights you have, any time you are not getting a light to work it is either a grounding issue or the 12 volts just isn't making it there. There are no other possibilities... You either have a ground missing or the voltage is not making it to the light. Take a volt meter and measure the voltage there to ground (the trailer frame or what ever is your ground) when you have someone press the brake pedal. Do the same for the turn signal wire too. If you do have voltage there, then it is a ground issue...

Re: Boat trailer lights

it's got to have power to the light for the tail light to work

Click to expand...

This is true. However you also need power to the brake and turn signal for the brake light and turn signal to work. Running lights are seperate from brake and turn.

Re: Boat trailer lights

3 biggest issues with malfunctioning trailer lights.

1. Bad Ground
2. Bad Ground
3. Bad Ground

Try your trailer plugged into someone elses known good vehicle.
Try your vehicle in someone elses known good trailer.

See which end has the issue before changing out stuff.

Re: Boat trailer lights

10/4 I will try that and see what happens thanks for the help

Re: Boat trailer lights

There are 2 wires going to each tail light. The driver side will have a solid brown and a yellow/brown wire. The passenger side will have a solid brown and green/brown wire. The solid brown wire going to each tail light is for the parking lights and any side marker lights - these just burn steady. The yellow/brown and green/brown wires are for the stop and turn signals. So it sounds like your solid brown colored wire is connected (you have lights), but the wire for the stop and turn signals is not making good contact with the light.

If it were a ground issue, you'd have no lights at all on that tail light. Some lights don't have separate grounding wires on each light (just the white wire at the plug) -- the bolts on the lights will actually make the ground connection to the trailer frame -- so make sure that area is not too rusty so the bolts will make a good connection with the frame.

Re: Boat trailer lights

Fixed the problem. It was the connectors on the lights. Had to squeeze together with pliers so it was tighter to plug.

Re: Boat trailer lights

Good for you. Suggest re-making all connections and then making them waterproof.