My car a highly modified 1951 Studebaker, which was professionally wired (but with some issues I had to fix) now has a problem with the turn indicators. They had been working normally until recently. Now they work just fine as long as the head lights ae off. As soon as the headlights or parking lights are turned on the flashing stops. Also, the 4-way flashers also do not work when the headlights or parking lights are turned on. I have gone over the wiring as much as I can without tearing it all apart and have found no problems. The taillight bulbs are Leds, but the front turn indicator/parking lights are incandescent bulbs. I have Led compatible flashers for both the turn indicators as well as the 4-way flashers. Any ideas would be greatly appreciated. Larry