Check the flasher.
To fix the tag lights on a 1991 Toyota Tercel, first, check the bulbs to see if they are burned out and replace them if necessary. Next, inspect the wiring and connections for any signs of damage or corrosion, and repair or replace as needed. If the bulbs and wiring are in good condition, check the fuse related to the tag lights in the fuse box and replace it if it’s blown. Finally, ensure the light sockets are clean and making good contact with the bulbs.
If the bulbs all come on but do not flash then the flasher relay is defective and needs replacing.
Check bulbs or wireharness at back of bulbs.Switch handle that turns lights could be bad Toyo joe
It could be dirty contacts. It's hard to get all that tan-colored crud out of there.
You have to replace front and rear bulbs.
Check all of the three bulbs try replacing with working bulbs this should resolve the issue unless you have a bad module.
A blown bulb. Check fuses and then start replacing the bulbs one by one.
Try replacing the turn signal flasher
probably because you need to get new light bulbs, go get that checked!! that's dangerous
Probably a ground problem. Find the common ground for the lights.
Check bulbs or may be problem in steering column Check bulbs or may be problem in steering column Check bulbs or may be problem in steering column
Try Replacing turn signal flasher