It is a two filament bulb. One filament maybe broken and shorting out to the other filament. A unbroken filament maybe drawing just enough leakage current from two circuits to stay on. Try swamping the bulbs left to right or just replace the bulb. This would make so much sense if it's true, I have ...

Sounds like a wiring fault of some kind, or perhaps the wrong bulb ? Bad grounds can also cause havoc, does it change wit h headlight switch position ? I will try to see if it does change with the headlights tomorrow. Is there really a definitive way to know if the grounds have gone bad? I guess I ...

I have a new to me 1997 Volvo 850R wagon, since I drove it home the front right blinker has remained full on. I mean it was solid and bright, almost as if it was the headlight. I have tried replacing the hazard switch relay to no effect. Oddly enough, it doesn't blink when you put on the turn signal...