Recently a buddy of mine informed me that my right tail light is out, but my brake light is fine. Yesterday I replaced the bulb and the tail light is still a no go. I know that all three bulbs in the tail light assembly are the same and they each have two filaments. After replacing the old one with a new one the tail light still doesn't come on , but the brake light still works. The left side is completely fine and everything on the right side works except the tail light.
What is the problem and how do I fix it?