I am having issues as well. I posted a previous thread about this, but wanted to add mu issue to this one.
76 02, changed out all lighting to LED, everything works in the rear. My front blinkers are the issue. The right one works, until I turn my head lights on. The left does not work at all, either way. If I leave my right one on for a bit then turn my left on, it blinks one time. If I turn my hazards on, they work. When I turn my head light on and try to use the blinker, then my radio lights flash. I have traded out the flasher to an electronic one, I have replaced the blinker assembly ( $350.00 that was a hard pill to swallow ) I have connected a direct ground wire to the blinker itself. These are a few things that were suggested to try, all with negative results.