There are a number of reasons that your signals might not be working. First off, I would check your fuses to make sure none of them are blown; next, check your bulbs. If those are all okay it might be your turn signal relay--in many car models these are located around the fuse panel somewhere, although they may not be immediately visible--also check to see if your hazard lights are working--if they are, and your fuses and bulbs aren't burnt it's probably your signal relay (note: there is one for the hazards and one for the turn signals) If your hazards and your turn signals are not working you may have a more in depth electrical problem, or both relays could be blown--however unlikely. One of the last things I would look at is the actual switch in the driving column that turns on your signals.
There are two flashers, one for the hazards and one for the signals.
check the fuse first!
The 1990 VW Jetta turn signals will not work when the ground wire is broken or corroded. The turn signals may need the lightbulb's replaced.
I replace my flasher fuse.Now they light up but won't blink.
Multifunction switch is bad.
Most likely a bad turn signal flasher or blown fuse
have you tryed all the fuses then check if the bulbs are good
If the turn signal bulbs light but will not flash, the flasher relay is defective, replace it.
Could be the flasher unit.
replace flaser can in fuse box
Your problem is most likely the turn signal relay im having a problem similar to yours but when my signals wont work neither do my hazards
The turn signals and hazards are on separate relays. You need to replace the signal relay. If that doesn't do the trick, look into your turn signal switch.