Only one of my blinkers was actually blinking on the instrument panel and on the taillight so i dug around and found that i had two flashers. One mounted behind the instrument panel and one hanging under the dash. My right taillight blinks and makes the click noise like usual but my left one is just a solid light both on the taillight and the instrument panel. One of the flashers is made of plastic and the other is made of metal. Is this common for '68 f-250?