Why is the left turn signal blinking fast on your 2005 Dodge Neon after replacing both front and rear bulbs?

Double check the bulbs you replaced, you may have installed one incorrectly or one of the bulbs is faulty. See sources and related links below for bulb information.

I have seen that the turn signal flasher can cause this to occur. One side flashes faster than the other side even though all bulbs are working. The remedy is to replace the flasher unit.