Shorelandr Trailer - Where is the ground wire connected to the trailer?

[Chadharter]

I'm having an issue when hauling my boat where my truck will display a trailer light fault and then it goes away and is fine. Sometimes it says trailer disconnected and then it reconnects. It does this off an on intermittently. I'm thinking there could be an issue with my ground wire. Does anyone know where the ground is actually connected on the trailer? I can't find it anywhere. My boat is a 2017 FSH 190 Sport and the trailer is the Shorelandr trailer that came with that model year. Any help would be appreciated. Haul vehicle is a 2021 Ford F-150. I now the issues with the trucks are well documented too, but I'm trying to eliminate the ground issue first.

Thanks,
Chad

 

[FSH 210 Sport]

I occasionally get a similar fault and it’s always the right blinker light on the trailer. I just disconnect the plug once or twice and the fault clears. I’ve never had an issue with other trailers. Might not be a bad idea to clean the trucks connector and the trailers’ plug and see if that helps. Use a test light to confirm there’s no 12V power at the truck plug before you start cleaning.

To your question about the ground location, I do not believe the trailer lights use the chassis as a ground connection, I think the grounds all come back to the 7 pin plug ground point.

Here’s the diagram;