More electrical gremlins after side wall replacement…running lights shorted to ground

[Drstimpy]

I’m again looking for the wisdom of the group to help me make sure I have done all the quick and dirty solutions for running light circuit shorting to ground. Our rig went to Indiana for service where they had to remove the entire driver side fiberglass wall to replace it because of cracking. It came back with an inverter that won’t run the refrigerator (prior post) and a running light circuit short. Again, this will be covered by warranty, but they have to keep the rig for a number of days during prime camping time. And now it’s a safety issue because I can’t legally drive the rig at night without running lights. So, what is the first thing you would do if you were looking for a running light short to ground?
Thanks

[Vicr]

So how do you know the lights are shorted to ground? Is the fuse blowing immediately after you turn on the running lights? If so you need to isolate the lights in sections, disconnect the incoming hot and the outgoing hot in a string of lights and check for continuity from hot to ground, do this for each section of lights. then check between each section of lights for continuity between hot and ground. Once you find a section of wiring where the hot has continuity to ground you can abandoned that wire and run a new one. It's going to be a PITA but isolating the shorted section is the correct way to find the issue.

[Drstimpy]

I tested at the trailer plug and the running lights are short circuited to ground. Just to be sure I hooked up the truck and it blew the fuse right away.

[Drstimpy]

To close the loop…
The front driver side marker light wire was cooked. The screw that held on the light was sharp and too long. It violated the insulation on the hot wire. The install was simply bad excrement.

[Vicr]

Glad you found the problem so quickly!