Troubleshooting Optronics LED Identification Light Bar MCL97RPG Blowing Running Light Fuse

Question:

Hello, I have Truck and Trailer Identification Light Bar - LED - Submersible - 9 Diode - Red Lens Item # MCL97RPG on my boat trailer, I had to re-wire the connections because they were corroded. I did not have any problems for awhile and now the light bar is blowing the fuse on my truck for the running lights. Brake and turn signal still works. When I remove the light bar and replace the fuse it works fine, but when I screw the light back on the trailer it stops working. It is a ground issue, I think, because I can back off slightly on one the mounting screws and all the running lights come back to life. Do I need to replace the light bar, or do I have another issue. Im assuming the ground for this light bar is the mounting surface? When the bar is not mounted it doesnt work, but when I touch it to the trailer it works. Any help would be much appreciated! Thank you

asked by: John S

Expert Reply:

The Optronics LED Identification Light Bar # MCL97RPG is a single-function clearance light that connects to your running light circuit using a 1-wire hookup for power since it does indeed ground through the mounting hardware. For this reason the light working when you touch it to your trailer is perfectly normal.

If there is corrosion inside one of the lights this could be causing the short that is taking out your fuse. It sounds like there could be damage inside the unit that is only revealing itself when you have the mounting screws applying pressure to it. The problem could also be worn insulation on the +12V power wire that is shorting it to ground.

expert reply by: Adam R