So I recently lost the plastic cover for the front turn signal on my car, leaving the bulb exposed. It worked for awhile, but the rain finally got to it and the bulb went dead, and the blinker went at 2x the standard rate, indicating i had a bad bulb.

After getting a new turn signal, I put a new bulb in there. The bulb lights with my parking lights just fine, but when my turn signal goes on, it still blinks at 2x speed (even though both bulbs work.)

So my question is, what could cause this? What regulates turn signal blinking speed, and how easy is it to replace?

Thanks
Phil