Just installed LED tail lights in 2004. Turn signals flash very fast. Instructions say to check front bulbs-ok Then maybe voltage low to start car-ok Still no change. thought of a different flasher maybe some type of heavy duty Does anyone have a clue thanks

 

I have the exact same problem......and yes, same as you...all my bulbs work. I haven't called the company yet...can't remember right off hand who makes them....to ask what the heck is up with it. I'd be interested to see if anyone has a fix for this too!

 

I'm not sure what the flasher circuit looks like in the C5 but if it's like the older cars with the bulb in series with a thermal flasher then the problem is most likely that the LEDs draw less current than a regular incandescent light bulb. The Flasher is designed to flash faster if a bulb is out (less current).

I'm surprised that the LED lamp manufacturer didn't take this into account (if it is the problem). Try replacing one side with the old bulb and see if that side works ok.