I have a 2009 Mustang GT convertible. My left turn signal is blinking fast. When I checked one bulb was out the third one in a row of three from left to right. I replaced the bulb and it still does not work. I put the new bulb and the old bulb in the second or middle position and they both work..Can anyone tell me what may be wrong. The tail light portion of the bulb in the third position works fine.

Ray

 

What about the front bulb?

 

On the factory 05-09 tail lights, the inner bulb on each side is not factory wired to function as a brake/turn indicator. If one side flashes faster, as mentioned, check the front bulbs too.

 

If you found one burned out, you may have another. Don't be cheap, go spend a few dollars and get a pair of new bulbs; you probably have two out anyways, or that one may be still causing your fast-blink. Change it, and check the other two while you are at it.

Seems like all of my brake bulbs and backup lights failed around 4-6 years old. You could replace all of them on one side while you are at it to save time later, then keep the geed bulbs as temporary spares.