My light comes on (very, very dimly) and the tank is full. When I start the car, it doesn't show at all. But after driving a few miles the light comes on at a super dim level. I even unplugged the sender sensor and the light still is coming on dimly. What in the world? It's annoying at night because it's more apparent. Any suggestions? This only started a few months ago. Came out of the blue.