Turn Signal Blinking Fast But Bulb is Good : Causes & Fixes

If the turn signal is blinking fast, but the bulb is good, it is because your car’s wiring system gets heated since it is close to the engine compartment. The other reasons are water or moisture formation, the car’s vibration, driving on a shaky road while off-roading, etc. Based on my experience as a mechanic, I have sorted out the causes and solutions to the fast-flashing turn indicator in this article.

Cause 1: Damaged Wire

After supplying the electricity for a long period, the wire gets weak for several reasons, including:

Corrosion: Often, our cars come into contact with water and moisture. Water and moisture form rust on the joints of the wires. Corrosion damages the wire, disturbs the flow of electricity to the bulb from the battery and causes your turn indicator light to blink faster.

Clogged with debris: Obviously, every car is driven through the dust. Sometimes, debris flies and accumulates on the wire connections. They also interrupt the electricity flow and cause the turn indicator light to blink fast.

Damaged wire insulator: All the wiring systems of your car are near your car’s engine, which gets very hot when you drive it. After driving for a few years, it affects the rubber-coated electric wire, as the coating is thin. When the rubber coating is gone and the wire is exposed, there may be a short circuit that also causes any of the turn indicator lights to flash faster.

Torn wire: When the corrosion is too much, the wire may be torn out, and the connection may get faulty, causing the turn indicator to flash faster. Don’t worry; I have the easiest solution for you if the wire is damaged.


I will give you some simple inspections so you can solve your problems on your own.

  • Check your turn indicator light’s fitting first to see if it is tight or not. If the light bulb is loose, tightening the bulb will solve the issue.
  • Clean the bulb with the electrical contact cleaner to remove any rust or corrosion. It will be better if you put some anti-corrosion spray on it.
  • If the amount of corrosion and rust is out of your reach, you can take it to the nearest auto repair shop. You will need a wire brush to clean the debris and thick rust.
  • When you see the wire’s insulation is damaged, you need electrical tape to fix it.
  • You need to check each electric wire individually and replace faulty wires.

Cause 2: Faulty Relay

A faulty turn signal relay causes the turn indicator light to blink faster, indicating something is wrong with the relay. The frequency of blinking the turn bulb depends on the relay.

There is a flasher with the relay. A thermally controlled flasher has a simple electrical mechanism inside it when the circuit is completed as you hit the indicator arm.

It heats up and completes the circuit. The relay fails to function due to poor contact alignment in an open coil structure.


If the relay is the issue, you must replace it. Follow these 2 steps to replace the relay.

  • First, gently put your fingers on the flasher and check if it is ticking properly. If there is any abnormality, pull it out.
  • Carefully read the part number, match it with the new relay you can get at a motor store, and swap it with the new one. Before turning on the switch, ensure the flasher is fitted tightly.

Cause 3: Malfunctioning Circuit

There are many reasons for a circuit malfunctioning, but in most cases, it tends to malfunction when the circuit and bulbs are bought aftermarket.

A fast-blinking or hyper-blinking issue arises when the circuit is damaged or has a short circuit in it, and another possibility is a mismatch between the circuit and the flasher relay.


I have a solution for you if you are facing issues with the circuit.

  • First of all, inspect your circuit connections to see if they are okay or not.
  • Check every wire, and make sure no wire is exposed to another. If all is okay, you have an issue with the flasher relay.
  • I suggest you check the part number and investigate whether this flasher relay is compatible with this particular circuit. If it does not match, change it immediately.

Cause 4: Burn-Out Fuse

The turn signal light fuse in your car may burn out for several reasons, including:

  • Loose connection
  • overload of electricity
  • Corrosion of the wire
  • Faulty circuit
  • Short circuits


I have discussed most of the topics above, except overloaded electricity. Now, I will tell you how to change the damaged fuse.

Follow these 5 steps to replace the damaged fuse.

  • First of all, take the plastic cover out of the fuse box. You will find it under the dashboard of the driver’s compartment.
  • Carefully look at the diagram under the fuse box cover; you will find the turn signal light fuse.
  • Check the fuse with a test light. The test result will tell you the fuse condition. If you find the fuse burned, pull it out carefully.
  • Replace it with the new one, but before that, ensure it has the same current rating as the previous one.
  • Then, put it in the same place as the previous one. Fit it properly and put the cover back.

After finishing the setup, check all the nearby fuses to see if they are tightly fitted or not. Try to avoid touching other fuses while unplugging this one. Otherwise, it may cause new trouble.

Cause 5: Faulty Turn Signal Switch

Sometimes, a fault in your car’s turn signal light switch is responsible for the hyperlinking or faster flashing of the turn indicator light. In that case, it is a good decision to swap the switch instead of repairing it.


Replacing the turn signal light switch is not as hard as you think. To replace the turn signal switch, follow these steps:

  • First of all, you need a screwdriver. Pull the steering wheel up and expose all the screws.
  • Remove the airbag from the steering wheel. The steering column trim and clock spring will be visible.
  • Remove the clock spring with patience.
  • Now, you will be able to swap the turn signal switch.

After changing the lever, fit the screws carefully and tightly. Don’t miss any screws.

Final Thoughts

You can solve the fast-blinking turn signal light issue in your garage. If you are not confident enough, I would not recommend you perform any of the tasks I mentioned in this article; rather, I suggest you call an experienced mechanic. It will cost some bucks but will be better for you and your car.

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