Whole trailer flashes with hazards on

This can easily be a bad ground issue.

The grounds are a common circuit for all the lighting giving every light an electrical path to every other light. When a ground is broken at a given point current will pass through a light To complete the circuit.

In this case the lights are flashing when the 4 ways and running lights are on. Betting the flashing is all the running lights are blinking on and off. Most likely cause is the running light ground is broken. the running lights are using the brake/turn circuit as a ground. When the 4 ways are on the running light path to ground now has on/off power removing the alternate ground path.

 

You could just climb under trailer and look for loose/broken wiring...or if that doesn't work, start at the trailer connection and work your way back.

Negative Ground = power travels from ground to positive lead on Battery....The chassis is "electrically charged with negative electrons. The electrons travel from - to + so the problem could be in the socket, broken or defective, test the socket for continuity.

You will also need a schematic ( wiring diagram to trace the problem) specific to the equipment you are testing. IE, the Trailer Brand and Model.

 

Prime example. Not 30 minutes ago I had a customer drop off a utility trailer with tail light issues. The marker lights were lighting up when the brake lights came on. Diagnosed and repaired a bad brake light ground and everything works perfect now.

 

Where was the broken ground?

 

This is an interesting schematic. What is it from? It's different from any tractor/trailer plug I've ever seen. Usually blue (auxillary) is in the center. Ground at the top. Left and right signals (yellow and green) across from each other at 10 & 2 positions, and tail and clearance (brown and black) at 5&7 positions, red (brakes) right at the bottom. Hope nobody tries to use this one for a normal trailer, it ain't gonna work.

 

There are literally hundreds of these 7 pin connectors on the open market..... There is no universal wiring design!

"You will also need a schematic ( wiring diagram to trace the problem) specific to the equipment you are testing. IE, the Trailer Brand and Model."

 

Hundreds of 7 pin connections? Lol. This thread gets funnier by the minute

 

Ok I will narrow it down a bit .......

Hundreds of different types of trailer connectors.....My Bad!

 

I picked up a 7 way rv plug for a small utility trailer the other day and the wire colour codes writen on the new plug were 100% wrong compared to the old plug and 3 new pickups I looked at in the parking lot.

 

Dang look what I started...I had alot of ground issues on this trailer because I had alot of running lights that weren't working also so I took them off buffed the ground and put some grease on them...that fixed them right up so I now have all my running lights. Also had some wires broke on some running lights and fixed those...I still have the issue butni needed to haul for the last couple days with it so I had to pull it out of the shop...I need to do brakes on one of the wheels so I was gonna get more advanced diagnostics then...thank you everyone for your help