67 Barracuda Turn Signal Dielemma

My name is Ken and I'm new to this forum, wondering if anyone has come across this one. I have an issue that has popped up on my recently purchased 67 Barracuda Convertible. Turn signals work fine with headlights off. With headlights or parking lights on the the dash indicator for the left turn signal is always on unless you activate the left turn signal in which case it will flash in the normal fashion until its shut off and it returns to the stay on status with the lights on. Shut the lights off and it goes out. The previous owner had the instrument cluster was professionally restored. This is a recent development and wasn't doing this the first time i drove the car at night. I have only had the car for a little over a month and only drove it twice as I live in Massachusetts salt country this time of year. Barracuda.jpg