Running Lights Fuse Keeps Blowing - Any thoughts?

[tripwire]

I have a little single axle trailer that I use to pull my boat. Recently, the fuse for the running lights started to blow on the Suburban. I backed my trailer into the lake without pulling the plug from my Suburban on Memorial Day, and that night on the way home I couldn't get the running lights on the trailer to work. The brake lights and blinkers worked fine. I found when checking that I had no power coming to the pin on the Suburban and traced it back to a blown fuse. I replaced it. The lights then worked. The next time I drove the trailer it blew again. It blew again when I took the boat out yesterday. I checked all the lights when leaving the lake, and they all worked (including the running lights). By the time I got home, the running lights were not working again.

My trailer has the four pin inline connector. I have an adapter that converts it to a round connector that matches up to my Suburban (6 or 8 pins). Does anybody have any ideas about how I can trace out what is causing the fuse to blow?

Thanks!

 

[Splat]

Re: Running Lights Fuse Keeps Blowing - Any thoughts?

Check for water in the lights.

then I would check for corrosion in the 7round plug on the truck

Finally start checking wire on the trailer, especially pay attention to areas where the wire either goes into a wire clamp, or in and out of the trailer frame. Look for chafing and a possible short.

Bill

 

[wirickdg]

Re: Running Lights Fuse Keeps Blowing - Any thoughts?

Thanks for the reply. I will also check the 4-pin to 6-pin converter. I know that one of the pins on the 4-pin is a bit mangled. Maybe I'll just replace the connect and turn it into a 6-pin on the trailer for simplicity.

 

[wellsc1]

Re: Running Lights Fuse Keeps Blowing - Any thoughts?

You got an intermittent short in the running light wiring, either along the trailer, in the tailights, or at the connector. I had a similar problem with my anchor light, which turned out to be a screw that chafed the insulation and boat vibration would short it out occasionally. Unfortunately, the wire was inside a tube and a beast to troubleshoot down to it.