Turn Signal Blinking Fast | Why & How to Fix

INTRODUCTION

The cause and solution of the problem of LED turn signal flashing quickly are the focus of this article. The LED turn signal is the main device used to indicate the dynamic information of the vehicle. It is installed at the front and rear of the vehicle body and turns on when the vehicle turns. Through the turn signal, we can convey the message of the vehicle's next move to the surrounding drivers and pedestrians to ensure driving safety. The LED turn signal bulbs can emit bright and clear light beams, which can effectively convey the next driving direction of the vehicle to the surrounding people in a timely manner, which not only increases driving safety, but also improves the aesthetics of the vehicle.

However, when upgrading a vehicle to LED turn signals, the LED turn signals may flash faster than normal, a phenomenon known as hyperflashing. This doesn't mean there is a problem with your vehicle, it's just that LED bulbs require less current to generate enough heat to heat the internal wiring and open the circuit, so they won't work properly with the flasher module. At this time, the vehicle's computer system (CANBUS) will detect this problem, think that the bulb is faulty, and display an error message on the vehicle display, and convey the fault information to you in the form of  hyperflashing. So the following are the detail information about the causes.

WHY IS MY TURN SIGNAL BLINKING FAST

First, we need to understand the basic principles of turn signal operation.

The power source of the turn signal comes from the fused hot wire in the junction box under the hood of the car, and this hot wire supplies power to the turn signal switch through the flasher module. When the driver raises or lowers the signal control arm, the circuit is switched on, supplying power to the front and rear turn signals on the side of the vehicle. The flasher then connects the current to the signal bulb in the vehicle, and the current flowing through the tape is straightened and bent to break or complete the circuit to produce the flashing motion.

So, there are two main reasons for a fast blinking turn signal.

• When you install an LED turn signal in a car that did not originally have LEDs, the turn signal will blink much faster than normal and appear to be Hyperflashing. This does not mean that there is a problem with your car, but rather that the LED bulb requires a small amount of current and does not draw as much power to heat the internal strip and open the circuit, and therefore does not work with the flasher module to work together. At this point, the onboard computer system (CANBUS) will trip and the vehicle will determine that there is a problem with your bulb and an error light will appear on the vehicle display and communicate the fault message to you in the form of a super flash.
• The LED bulb is overheating during operation and the hyper-flash is trying to warn you to turn off the blinker and let it cool down. After a few minutes of shutting down, the LED turn signal bulb will resume normal flashing once it cools down.

EFFECTS OF LED TURN SIGNAL LIGHTS BLINKING TOO FAST

The question of whether flashing lights are illegal is controversial, and their legality depends heavily on the exact speed at which the flashing occurs, and the state of the vehicle at the time of driving. The Department of Transportation generally sets the speed at which a vehicle's turn signal flashes at 120 times per minute, which may be a violation of the law if the problem of fast flashing turn signals becomes too serious. However, normal turn signal flashing speed is not a problem and is relatively more secure and safe. In addition, excessive flashing of signals is harmful, and this is relative to others. Super flashing lights can be a huge distraction to other drivers and can lead to serious accidents or injuries as they take their eyes off the road. Therefore, the problem of excessively flashing LED turn signals needs to be addressed.

MARKING LED TURN SIGNAL LIGHTS BLINKING TOO FAST 

We can tell that the car is flashing too fast when the following conditions occur:

• When you stand outside the car and turn on the turn signal, one side or both sides of the turn signal blinking fast but bulb is good.
  
• When you turn on the turn signal inside the car and you hear a fast blinking noise (i.e., a faster-than-usual clicking sound).

In either case, you can follow the clicking sound inside the car to find the location where the turn signal bulb is installed and have it checked.

SOLUTIONS TO LED TURN SIGNAL LIGHTS BLINKING TOO FAST

Fortunately, there are three general methods to simply fix the LED turn signal blinking fast.

• Installing Load Resistors

A load resistor is a resistor that is placed between the positive and negative wires of the LED turn signal wiring. This will create a bridge between the two wires and will eventually increase the load on the entire circuit. The circuit's load is increased to simulate the power consumption of the original bulb, tricking the on-board computer system (CANBUS) into thinking that the power of the light bulb is the same and identifying it successfully. Then the Flasher module works normally to receive the current and cancel the fast flashing situation. 

• Installing LED bulbs with bulit-in load resistors

LED bulbs with built-in load resistors are called built-in resistors. It replaces traditional filament bulbs with CANbus-compatible LED bulbs. These LED bulbs have additional resistors built into them that help adjust their characteristics so that they are closer to the parameters that the CANbus system is looking for, thus solving the problem of excessive flicker.

• Installing an LED flashing relay

Typically, your vehicle is equipped with a relay to coordinate the blinking speed of the turn signals. This is generally the direct source of how your super-flash problem occurs. Because the flashing relays that usually come out of the automotive factory are designed for regular incandescent filament bulbs and are not compatible with LED bulbs, you need to change to a hot flashing relay specifically designed for LED bulbs to match, which will solve the super-flash problem.

Each of the above three methods has its own advantages and disadvantages. It is important to note that some vehicles may require a combination of both solutions to overcome the issue. It is also recommended to use high-quality LED bulbs and resistor kits from reputable manufacturers to ensure optimal performance and avoid potential safety issues. Therefore, to choose which method to use to solve the problem of fast flashing LED turn signals, it is best to understand how your particular LED turn signal bulb works and choose according to the vehicle needs.

Of course, if you feel that the above three methods are troublesome and do not want to do it yourself, you can contact professional technicians to provide help and problem solving.

Also, if you notice one or both of your turn signals flashing quickly while your direction lights are still working, this is not necessarily an issue with LED compatibility. It could be due to a damaged bulb, insufficient voltage, or a ground fault. It is important to accurately diagnose the cause of the problem and choose the appropriate solution accordingly.

CONCLUSION

Nowadays, as automakers continue to seek innovative design ideas and reduce the cost of core materials, the use of LED lighting throughout the vehicle will continue to grow. LED indicators seem to be inherently safer because they warn other road users of the driver's intentions more quickly. If you are already equipped with LED turn signals and have experienced hyper-flash,or you are considering using LED bulbs installed as turn signals, I hope this article will be helpful to you.