Whole trailer flashes with hazards on

Most wiring issues are because it wasn't done right the first time.

 

Try unplugging one light at a time,might narrow the search some.

 

Not grounding. No ground, NO NOTHING. I think two wires are shorting together. Keep in mind people. If you have no ground you have no power. You need both + and -

 

Just a dirty ground would do that all day long.

 

A bad ground or dirty ground will not cause the problem he is seeing. All his lights are going bright instead of only the ones that should. There is a separate wire that goes to your brakes, directionals and flashers. If all his lights are flashing bright chances are that wire is shorting out to the normal running lights wire.

Still.
No ground, No light.
No power, no light.

 

Think what you will. Experience tells me otherwise.

 

Lol

 

All his lights work fine , till he turns on his running lights (the ones that really need a good solid ground) then he starts having issues. If he had a had a wire crossed then they would be causing trouble all the time, not just when you put power to the running lights.

 

I can't count how many pieces of equipment and trucks I've worked on over the years that have bad grounds that cause similar issues. Electricity will take the easiest path to ground. If it is easier to ground through another light or group of lights, it will. I will agree with you skate board that shorted wires can cause the same issue.