Turn Signal Flasher Replacement

Turn Signal Flasher
How to Replace a Turn Signal Flasher

Flashers are an important electrical component that allows yours turn signals and hazard lights to blink. The flasher is usually located in the power distribution center. There are four main types of flashers for automotive use; turn signal flasher, hazard warning flasher, two in one combination hazard light-turn signal and alternating flashers used in emergency vehicles. Flashers are designed to alert both the driver and others outside the vehicle to see that the vehicle intends to turn left or right and give early warning of such a move. 

The flasher will also emit an audio clicking sound to alert the driver the turn signal has been activated. The turn signal flasher will illuminate only the left or right turn signal bulb while the hazard warning lights will illuminate front and back and left and right bulbs. When blinkers fail it can mean that either you have a bad bulb or a failed flasher. One of the symptoms of a failed bulb include rapid blinking, no blinking or blink rapidly.

Thermally activated Flashers: Some are thermally activated by applying a current when the blinker is turned on; a resistive wire that is wrapped around spring steel expands in the flasher and completes the circuit triggering the turn signal light bulb for an instant. Once contact is made in the flasher the spring steel cools and returns to the off position awaiting another pulse of electricity to repeat the process as long as the blinker is on. This usually lasts less than a second.


Step 1 - Locate your power control center and identify the turn signal relay by consulting your owner’s manual or a repair manual

Step 2 - Remove the failed flasher by hand and compare with the replacement flasher to ensure that they are identical.

Step 3 - The electrical connectors on the flasher can only be inserted one way into the power distribution center so installation is a cinch.

Step 4 - Visually inspect that all the blinkers and emergency flashers work

If further technical assistance is needed, our certified car repair technicians are ready to answer your car questions. For manufacturer specific repair information visit - Car Repair Manuals

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Article first published (Updated 2013-08-16)