Type and age of vehicle would be helpful. But it is probably a short in the turn signal/brake light system. I had that problem once and it turned out it was a bad filament in one of my tail lamps.
Turn left indicator signal flashes rapidly when I use indicator, bulbs ok, no lights working
Make sure all bulbs are working Replace turn signal flasher
It's the turn signal indicator-located behind the hazard lights.You have to take it out and replace it.
How bout the turn signal indicator switch located in the steering column.
It sounds like you have a turn signal bulb out probably the left rear.
You have a ground issue. More than likely it is not grounded properly. These can be very, very, hard to find. Been there and done that. I can only tell you to check all ground connections at the taillight assembly.
If you are getting an indicator of a burned out light, but don't see a burned out light, it must be a turn signal light. On a Mercedes, you'll actually get a "burned out light" indicator if the turn signal is not working.
These symptoms indicate that there is either:a failure of the signal light switcha bad ground in the signal and head light circuits.
You have a turn signal light-bulb out .
The front turn signal bulb is blown. This is a feature of all modern cars, so that the operator becomes aware that the bulb is not working.
Sounds like the turn signal indicator lights.Sounds like the turn signal indicator lights.
The turn signal indicator relay switch can be found below the dashboard on the drivers side. The signal indicator relay switch should be labeled as such.