it is the switch good luck looking on how to change myself
Could be the flasher unit.
There are two flashers, one for the hazards and one for the signals.
check the fuse first!
I replace my flasher fuse.Now they light up but won't blink.
Unhook the battery to stop them, and probably the control module or switch went bad and that's the reason they wont turn off.
replace turn signal flasher, hazard flasher is separate
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.
Most likely a bad turn signal flasher or blown fuse
Replace the Flasher Relay. Located Front seating area, driver side, behind left hand side of instrument panel, on fuse panel.
turn key over turn key over
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.