Hello and welcome to just answer. When you turn on the left turn signal, does the left rear flash fast like the left front does?
Oh, ok, you initially said that it was the left front that flashes too fast. If it is the right front that flashes too fast, and nothing at the right rear, then the right rear stop/turn signal bulb has probably burnt out and replacing that bulb will take care of this problem.
If you need the procedure on how to replace it, then tell me the model of your Chrysler, and I will be happy to send that to you.
Well it could be a failing bulb socket assembly. I have seen where the terminals in the socket get overheated because they fit loosely where the bulb's contacts connect to the socket terminals. This can cause excessive heat in that area and cause premature bulb failure. So when you go to change the bulb, inspect the terminals in the socket and replace it if you see signs of discoloration on the terminals. The #1 cause of a fast flashing turn signal is a burnt bulb.