A message on my instrument info center came on stating that the left
taillight was not working.  This happened 8 months ago with the right
side, so I changed the bulb and problem solved.  This time I replaced
the left bulb and it still is not working.  The brake light works fine,
but no taillight.  I went and bought another bulb just in case it was
defective, but I got the same results, no taillight, only brake light.

Can someone advise me on what I should do/try next.

Thanks in advance to those that help.