my left turn signal goes mad fast all of a sudden. works fine with right signal and works fine with flashers. I know my alternator is going to die soon and I have one on the way so I am going to go ahead and assume the blinker issue is related to the alternator just freaking out... but i am basing this apon absolutly no real knowlage

 

Look for a burnt out bulb. The lighting system is designed to do that in order to let you know that there is a problem with the system. It isn't related to the alternator.

 

I agree with the previous post, you have a burned out bulb on that side.

 

Ditto...
Has nothing to do with your alternator...
Alternator does nothing but supply a charge to your battery as it is continuously drained by the electrical system.