How to Repair Rapidly Blinking Turn Signals

Turn signal indicators or blinkers as they are called work in a specific manner which is dictated by the turn signal bulb and circuit resistance.

How Does It Work?

A BCM or flasher unit is incorporated into the turn signal system and is used to momentarily interrupt the circuit to create the blinking action. This system works on the resistance normally present in the lighting system.

What Goes Wrong?

On older vehicles a turn signal flasher is used to control the blinking intervals while newer systems use a BCM (body control module). When the system resistance changes either by a missing or burnt out bulb, blown fuse or corroded connection the blinkers will cycle more rapidly.

Let's Jump In!

Turn the key to the on position, push the turn signal switch in the direction the system blinks fast in, right, left or both.
turn key on

Inspect both the front and rear of the vehicle to identify a directional signal bulb failure, remove the lens or gain access to the rear of the lens and remove the turn signal light bulb.
blinker bulb not working

Once the bulb has been replaced check the blinker operation which should return to normal, then reassemble. It is a good idea to add dielectric grease when replacing the bulb, this stops corrosion.
replace blinker bulb

Sometimes the bulb can be good and electrical corrosion is the problem. When the bulb is removed, inspect the electrical connector terminal condition, if a slight amount of corrosion is present it can be repaired using electrical connector cleaner and a small wire brush or Exacto knife. If excessive corrosion is present the connector must be replaced as in the example below.
corroded blinker connector

If all four turn signals are blinking quickly check the fuses on the BCM or fuse panel, if your vehicle has a turn signal flasher unit, replace it. If exact fuse or BCM locations or procedures are needed you can ask our experts to supply you with the information (free), or consult an online resource such as AllData DIY (pay).
check turn signal fuses

If everything seems to be working correctly a CAN scan (Controller Area Network) can be performed which can help pinpoint the problem as in a BCM failure or a TIPM issue in Jeep and Chrysler products.


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