Symptoms of a Bad or Faulty Turn Signal Lamp

Common symptoms include an illuminated turn signal light that flashes very quickly and the turn signal bulbs themselves do not flash.

Turn signal lamps are a common "wear and tear" item in your vehicle's electrical system. The bulbs on most cars use a filament that literally burns out, just like old household incandescent bulbs burn out at home. In some cases, a poor connection due to corrosion in the bulb socket or a problem with the bulb wiring can also cause a "no turn signal" condition. Since turn signals activate both the front and rear turn signal bulbs, most bulb failure scenarios can be easily diagnosed, although repairs are best left to a professional to replace the turn signal bulb. Some of the symptoms of a bad turn signal bulb include:

1. The turn signal indicator on the instrument cluster is on and does not flash

This is a common failure mode and can be tested while your vehicle is parked in a driveway or other safe location. To check which of the bulbs has failed, front or rear, walk around the car after selecting the direction of the turn signal to see which of the turn signals (for your chosen side of turn), front or rear, is not working. lit. For example, a continuous left turn signal with the front turn lamp on but the left rear turn lamp off indicates a defective left rear turn signal lamp.

2. The turn signal indicator flashes very quickly

This is another common failure mode. To check if the front or rear turn signal light is out, walk around the car (still and in a safe place, of course!) to see which of the turn signals (for your chosen side of the turn) or behind is off. For example, a fast flashing turn signal for a right turn with a fast flashing right front turn signal and no right rear turn signal indicates a problem with the right rear turn signal.

3. Both left turn lights or both right turn lights do not flash

This is a common fault with the turn signal switch itself. An AvtoTachki professional should check this condition and replace the turn signal switch if necessary.

4. Right and left turn signals do not work properly

This symptom can be observed if the built-in turn signal hazard/blinker unit itself has failed. This can be checked by pressing the hazard warning button in the vehicle. WARNING: Perform this test only off the road in a safe place! If the left and right turn signal lights do not flash properly, the alarm and turn signal unit is probably faulty. If the above symptoms and diagnosis indicate a problem with the alarm and turn signal unit, a qualified mechanic may replace the warning and turn signal unit.

Another possibility for this symptom is that an electrical overload in the turn signal circuit has blown a fuse, protecting the circuit but preventing the turn signals from working. Checking the AvtoTachki turn signals will show if this is the case.