Weisslicht Installation Guide for Anti-Flicker Resistors

Posted by David on


If you have recently installed new LED based lighting on your vehicle and find that your new lights are flickering, or in the case of turn signals, flashing at an abnormally fast rate, this condition is commonly known as Hyper Flashing. We know how frustrating this can be, but don’t despair. The fix for this anomaly is quick and easy.


But first, you may be asking yourself why this happened. A little backstory will help you understand what’s going on.

The answer is quite simple really, and has to do with resistance and electrical load.

The bulbs you are replacing are most likely incandescent. One of the most negative attributes concerning incandescent lighting is its inherent inefficiency.

Electrical current is passed to the bulb which in turn energizes a conductor in the bulb, referred to as the filament – usually a length of coiled tungsten between two terminals and surrounded in the bulb by an inert gas. As the electricity flows through the filament, it instantaneously heats up and begins to glow white hot, thus producing light. The light, however, is really considered a by-product of the heating process, where about 95% of the energy provided to the bulb is wasted as heat.

This is a huge contributing factor as to why people are abandoning incandescent technology and opting for energy efficient LEDs.

So, why are my lights flashing?

Your lights are flashing because the electrical system in your car isn’t detecting what’s supposed to be there. When you start your car, the electrical system performs a self-test where a pulse of power is sent to all exterior lights. The purpose of this test is to detect that all the bulbs are working. Since LED bulbs use significantly less power than conventional lighting such as halogen bulbs, the system does not detect the set point resistance and this is interpreted as a malfunctioning bulb.

The flickering is the pulse of power transmitted by the electrical system, and since the expected resistance is not detected, an infinite loop is created resulting in the flickering or rapid flashing of your new LED light.


The fix is easy and involves the simple installation of resistors to allow your LED lights to pass the self-test and operate normally.

What you’ll need to get started:

  • Your new LED bulbs
  • One resistor for each LED light
  • Two SkotchLock connectors per light
  • The first thing you’ll need to do is identify the wires that lead to the bulb. The bulb could have two wires or three wires. For example, turn signals will have three wires, one for power, one for ground and one for parking light power.

    There are several ways that you can complete the identification of the wires. You can use a manufacturer’s wiring diagram, a test light or multimeter.

    In each configuration, we will only be concerned with power and ground. In a three wire configuration where one lead is the parking light power, we will never make any type of modifications to this lead. Again, ONLY POWER and GROUND.

    Vehicle manufacturers usually use dark or neutral colors for ground, including black and brown and hot colors for power, such as orange and red.

    Once you have identified the wires you can begin to add the resistors.

    To do this, you’ll be tapping into the leads, not directly connecting wire to wire or inline. Everything must also be wired in a parallel circuit, not a series circuit. Have a look at the following diagram for a two-wire configuration:

    Now, have a look at a three-wire configuration, where the third wire supplies the parking light:

    Take a moment to familiarize yourself with how the resistor takes its place within the circuit. Notice that the connections are not inline, and the connections are bridged by the Skotchlock connectors. Also, the parking light power lead is not in the resistor circuit. If you were to add the parking light lead to the resistor circuit, the result would lead to overheating and failure of one or more components due to the fact that the parking light draws 12 volts at a constant rate.

    To wire up the resistor between the ground and power sides, place the power side wire along with the lead to one side of the resistor into the openings of a skotchlock connector and snap it closed by pushing down on the metal tab. This will tap into both wires and facilitate a connection between them. Repeat the process for the ground wire and the opposite resistor lead. That’s all there is to it.

    The resistor will make up for electrical load that used to be drawn by your incandescent bulbs, satisfying your vehicle’s electrical system self-tests.

    Repeat this process for each bulb you are installing.

    Please note that the body of the resistor is actually a heat sink. The reason for this design is to effectively shed the heat that is generated through normal operation. You’ll notice that the body of the heat sink has two tabs with a hole drilled in each tab. This is to facilitate the mounting of the resistor to the body of the vehicle, and it’s purpose is to allow you to mount the resistor away from plastic, wiring or any other materials that are susceptible to heat damage. If you leave the resistor dangling freely, it may come in contact with other materials in your vehicle that could melt or otherwise become damaged by the heat generated through normal operation. We strongly suggest you take advantage of this design element of the resistor body and take the extra time to securely mount the resistors properly.


  • Gather all the parts and tools you may need to complete this project, including 1 resistor and 2 Skotchlock connectors for each light.
  • Identify the leads – POWER and GROUND or POWER, GROUND and PARKING LIGHT POWER.
  • Use the Skotchock connector to tap into one side of the resistor and the ground lead.
  • Use the Skotchlock connector to tap into the opposite side of the resistor and the power lead.
  • Snap the skotchlock connectors closed to tap into both wires and bridge the connection.
  • Ensure you DO NOT wire the resistor inline or series, but parallel. Failure to do so will not allow enough power to be dissipated by the resistor and the Hyper Flashing will not be resolved.
  • Mount the resistors to the body of your vehicle away from plastics and other wiring.

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