Originally Posted by axeman
I've run into an issue with my new boat trailer. It is a 2012 BoatMate trailer for my Super Air Nautique 230. Since the trailer has LED lights, whenever I hook it up to my SUV (Mercedes ML) and I turn on the headlights all the lights on the trailer start flashing. If I press the brake pedal all lights work as expected. As soon as I let go of the brake pedal the lights start flashing again.
I've contacted BoatMate and they say its a vehicle issue. I've contacted my mechanic at the local dealership and he says they've never had that issue. I've called e trailer.com to see if they have a variant of the following adapter for my vehicle with no luck:
The issue is that the trailer has a 7 pin adapter tied to the wiring harness so it doesn't require a 4-pin -> 7-pin adapter like most older trailers do (at least that's how my previous Dorsey trailer was). When I spoke to the boat dealership, they said people with Land Rovers have run into this issue but they didn't have a fix readily available.
Any help is greatly appreciated!
Sounds like you may have a ground problem - similar problem below:
article from http://hitches4less.com/troubleshooting-trailer-wiring.html#6
Q: When I have my headlights on and apply the brakes all my lights on my trailer go out. What causes this?
A: You have a ground problem. In your situation, you have a ground that is strong enough to provide some lighting functions but not all. This is called a weak ground. When the taillights and brake lights are used at the same time it creates the maximum amp load of lights on the trailer. If a ground problem exists it will show at this point. The places to check grounds are as follows:
The connector on the vehicle should have a ground wire secured tightly on a clean surface to the frame. A wire attached to the body or a surface with undercoating, paint, or rust can cause a ground problem.
The connector on the trailer should have a wire from the connector secured tightly to a clean surface on the trailer.
Each tail lamp assembly at the back of the trailer also must be ground. This is done in one of two ways. The first is by a separate wire coming from the back of each tail lamp assembly and being secured to the frame. The second, and most popular, ground is achieved through the bolts of the tail lamp assembly. In this case, the lamp housing must be attached to the frame of the trailer. If the lights are mounted on wood or PVC material, the lights will not receive ground.
The last possibility to explore is in the trailer design. If the trailer has a tilting bed, it is possible the ground is not passing through the pivot point resulting in a poor ground. The solution to this is to route a ground wire from the connector at the front of the trailer to each lamp assembly at the back of the trailer bypassing this pivot point.