Hello, I have a 1996 GMC Yukon and my left rear turn signal and brake light are not working. The lights work when i turn them but the signal light blinks really fast and only the left front works. I replace the bulb in the rear and it still didnt work. The right rear is fine but it is only the left rear signal and brake light that doesnt work.

Optional Information:
1996 GMC yukon 5700 vortec

Already Tried:
replaced the light bulb