Turn Signal Indicator on When Headlights are Turned On.

[money pit]

When I turn on the headlights on, the left turn signal indicator on the dash goes on. If I put the indicator in the left hand turn position, the indicator light goes off but the left turn signal doesn't work on the left The right side is fine. If the headlights are off, both turn signals work fine. I checked and cleaned the ground to the front turn signal. The turn signal switch is about 3 months old and was working fine. Could it be a bad ground for the headlight? Thanks