Possible ground issue

a few thoughts, check the hood wire harness i remember having problems there with my fld and the turn signals. replacement of the harness was cheap and easy and normal stock at the parts counter.

the other issue is rather than a flasher unit the turn signals are controlled by the computer board where the dash indicator lights are and known for failure.

also check your bulb connections if the bulb is in backwards or the power is getting crossed the marker could back feed the turn signal.

 

Nice to see you here.

 

I had a problem when I picked up my truck that the turn signals wouldn't work with the lights on. They disconnected the chicken lights, and it's been working since. I'm going to try to hook these lights back up.

 

I had the same type of issue and it turned out to be power cord for the trailer corroded and power was crossing over somehow .. also heard of people using those silver tail lights having to power cross over too ..

 

i would start at the bulbs and work your way back threw the harness checking for rubs/cracks ect for anywhere that power might be getting from your parking light hot wire to your turn signal hot wire. also dont forget about your tractor tail lights.