Troubleshooting Weak Ground On Boat Trailer Where all Grounds Run to Frame  

I have a 2016 Ram with factory 4/7 pin connector plug. Trailer is wired with a 4-pin to connect to the truck. I initially had the white wire from the 4-pin grounded to the frame of the trailer. After doing many voltage tests I have come to realize that the trailer is not a good enough conductor, it seems. I say it seems because I tried temporarily connecting the white wire just down the left side, without the right side terminated to anything directly to the white wire coming out of the tail/turn/brake/license plate light at the back of the trailer. Also, the brown and yellow wires connected. Tail/turn/brake/license plate light lit up bright and all lights worked as expected. I had the brown wire spliced at the location of the side marker light, so I then connected the brown wire of the marker light to the brown wire end coming from the 4-pin, and then connected the white wire from the marker light to the continuation of the brown wire going to the tail/turn/brake/license plate light. The tail light function was then was dim and the license plate light did not light up the turn and brake worked fine as they are running on the yellow wire circuit. I have not tried connecting the white wire from the side marker to the white wire run between the tail/turn/brake/license plate light and the 4-pin. I assume this is the proper way to connect the marker light when you are not using the trailer as ground. I DID however have all the lights connected up with both side marker light grounded to the trailer and both tail/turn/brake/license plate lights grounded to the trailer, and none of the lights worked. I also made sure that all my ground points were exposed metal to ensure maximum ground connection. I did not think that this would be such a difficult thing to just install simple LED trailer lights on a boat trailer. Any advice would be much appreciated!

asked by: Joe