rear left indicator not flashing when headlights on?

[delphs]

Hoping an electrical guru may be able to point me in the right direction.

guy pulled up next to me today and let me know that when i indicated left all my rear tail lights except the left indicator flashed. I got home and tested and exactly what he said was happening. When i turned my headlights off the rear left indicator lit up properly but i could also see faint flashing of my tail lights.

right rear indicator works fine and so does front left and right indicator.

any clue as to where i should look to diagnose this one? assuming some wiring somewhere has gone bung. about a month ago i had someone reverse into my bullbar hard as well bending it upwards at the lower mounting points. not sure if this could have affected it?

[7mmMagnum]

A lot of rear tail light problems start in your trailer plug. Might be a good place to start looking.

[delphs]

Thanks mate yeah i spoke to a friend whos great at getting himself into similar situations and he said he was currently having a similar issue and it was his trailer module. i'll have a look there in the morning when its not raining and 3 degrees

[dave g]

Bad earth same were