Put the round adapter in the hole plugged the 5 way on the boat trailer to the adapter and just got a flicker of 1 bulb outa each of the taillights. Nothing else lit. I have LED lights on the trailer. Am I gonna have to change the boat to round to work? I really dont want someone splicing wires on the vehicle to make it work. ANY SUGGESTIONS..

You shouldn't have to. Check the obvious first. What kind of truck is it? If it's a later models vehicle be sure and check all fuses first. The trailer lights are on their own circuits now. Double check ground wires too.

Again, shouldn't be a reason to rewire. If you come up short of ideas give me a call at the shop. I do this for a living.

479-524-0111 I'm there 9-5:30 central time.

Buck

Frank, sounds like a bad ground to me. If you are getting a "flicker" then it means some juice is getting through. Get a 12 volt "source" (battery), and ground it securely to the trailer. Then take the hot lead off the "source" and thoroughly insert a wire into each of the "flat' five ways connectors. Each connector you wire direct, that part of the electrics should light up. If they don't, the problem is with ground of each unit to the trailer. If they do light up, the problem is "truck" side.

When I rewired my entire trailer along with going to all LED lighting, I ran a designated 12 guage "ground" wire to each individual light, I did not bother to ground to the trailer. Trailer "grounds" are 95% of the problems with boat trailers. So I just sidestepped the entire issue and made totally overkill waterproof connections.

First thing i'd make sure of is that the truck connector is wired correctly and then make sure the trailer is wired correctly...... I've run into more then a few where the person wired it up so it would work properly on THEIR tow vechicle but it wont work on anyones elses!!!

Frank, I assume you have a "came with the truck/tow-trailer package and has a factory connector? Russ