2009 mustang base.
taillight orientation view from rear of vehicle: | 3 | 2 | 1 | | 1 | 2 | 3 |

Hello and thanks in advance for your feedback. only lights 2 (middle) and 3 (outer) turn on for a left, right turn or emergency four way. Checked all bulbs and they are all good.
Questions
#1. why is the #1 light bulb not turning on?
#2. I have looked on-line and in the vehicle manual. Is there a fuze(s) that I should check?

Cheers!

 

Normal behavior. The #1 light up when you run the lights, but they don't light up with turn signals or flashers.