you need to replace the bliker can in the fuse box.
If the lights blink fast on either side of the car then this means you either have non-factory bulbs in the car or you need to replace your blinkers because one of your lights is out.
I would say that there is a miswiring of the blinkers.
It typically means you have a bulb on that side not working. Can't remember if it's front or back. It doesn't matter what end of the car the burned out bulb is on. Just compare the good side blinkers with the bad side blinkers. what ever bulb or bulbs are bruned out will be fairly obvious, it also help to do this check in the shade, makes it easier to spot the burned out bulb.
Check your bulbs and your flasher.
If both sides (right and left) don't blink on and off, the blinker "can" may be the culprit.
That's usually an indication of a burned out bulb.
One of the bulbs is burnt out.
Maybe a short somewhere...did you replace the flasher unit? No - it was blinking spuradically(?) - now I have to blink it manually and it won't blink at all with lights on.
You have a burned out bulb on the right side. Even a the side marker bulb will affect the turn signal
You have a blown bulb either front or rear.
my left turn signal on my 1997 dodge conversion van works fine,the right signal lights but does not blink,,,,any ideas
If you turn on your 1999 mustang v6 car and the right signal light stays on and doesn't blink and you switch the car off and then the left signal light stays on without blinking, then you need to see a mechanic.