Turn Signals Blink Rapidly

Turn Signal Blinker Light Lens
Rapid Blinker Repair

A flasher unit is incorporated into the system and is used to break and then reconnect the turn signal lighting circuit; this is what creates the blinking action. This flasher depends on resistance in the lighting system (front and rear bulbs) to operate correctly. If a bulb fails, the resistance in the system changes causing the flasher to blink quickly. To check for this condition:


Step 1 - Turn the key to the on position (do not start the engine). Actuate the blinker lever in the direction of the malfunctioning turn signal.

Step 2 - Inspect bulbs front and rear, replace failed bulbs as needed. If you have replaced the bulb and it still blinks fast, plus the bulb does not illuminate properly the ground circuit inside the bulb socket has failed. To repair this condition remove the bulb socket and replace with new.

Step 3 - If all bulbs are ok, replace the flasher unit, sometimes the resistance inside the flasher fails cause rapid blinker operation.

Step 4 - When the repairs have been completed recheck the turn signal system operation. (turn off key)

To replace the turn signal bulb on your vehicle remove the turn signal lens or remove the bulb socket by twisting counter clockwise, replace the bulb and reassemble. The exact procedure for all cars is different, for instructions on how to replace the turn signal bulb on a particular vehicle consult an auto repair manual.

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Written by
Co-Founder and CEO of
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-08-16)