07 Western Star Lowmax - Left turn signal

I’m having issues with my left turn signal. Right signal works. When 4-way is activated both left and right rear work and only front right. When I have left signal on, nothing works until I use a test light to see if any power is coming to the left turn signal then left will start flashing, only when test light is touching left turn signal wire. Anyone have had similar issue! I have unplugged all harnesses going to front and back of truck and still only right will work.

 

I will try and replace the light see if it makes a difference. However I did unplug the harness going to the front signal lights and still same issue, right works but not left.