So I plugged my boat up to the truck the other day to see if the lights on it still worked and everything acted crazy on the trailer lights. The boat was wired about 5 years ago and new lights put on it. I also went and plugged up to a regular trailer and it didn't work right either. I figured my 5 wire to 4 wire converter was bad so I ordered a new one from Hopkins. I put it on tonight and now the running lights work fine on the boat but nothing else works or lights up. Everything on the truck works fine. I gotta dig around see if I have a test light, I tried my multi meter but it's kinda hard to watch numbers instead of a light. Any ideas? I did redo the grounds on both boat trailer lights and the plug harness ground on the boat trailer, I put new self tapping screws into the frame with eye/ring connectors on the end of each ground wire. Thanks.

-Stephen

 

I am not sure what acting crazy means when talking about trailer lights??

5 years it could be as simple as things being corroded on the plug pins

If you don`t have a ground cable from the battery to the frame getting a good ground at the back of the truck can be marginal at best with a sheet metal screw .

Even cleaning the contact surface to bare metal

I have had to many problems with those flat 4 pin plugs and converter boxes I no longer use them.

 

Today I bought a 4 flat tester that plugs in and has a light for every each turn signal and the tail light wire. Everything seems to work ok until I turn on my headlights. Then only the running lights work. This is just the truck with no trailer hooked up. The socket on the back of my tail light where the grounds are soldered on and pretty corroded. I'm wondering that is a problem.

How do you not use a converter?

 

Do I need to have a converter that is powered and has it's own circuits for the trailer lights?