Left turn signal issues.

Here we go. Right turn signal works perfect. Left one stays solid when I hit the lever. When you turn on the headlights the green light for the left blinker lights up on the dash. If I pull out the hazard knob all blinkers flash correctly. I've checked the flasher and bulbs, and they are good. What next? Any ideas? Help!!! O ya, 71 Dart Swinger.