If your LED or HID headlight bulbs are not turning on, the cause is likely a polarity issue.

LED and HID bulbs are polarity sensitive, which means that if the positive doesn't line up with the positive and the negative with the negative, no power will flow from the vehicle to the bulb.

Below, we explain how and where to reverse the polarity on LEDs and HIDs.

To reverse the polarity:

1. Unplug the bulb from the vehicle socket
2. Rotate the bulb plug 180 degrees
3. Replug the bulb into the vehicle's socket

If you have decoders with your LED bulbs, there are two connection points and hence, the polarity can be reversed in two places.

1. From the bulb to the decoder
2. From the decoder to the vehicle's socket

Start by reversing the polarity from the decoder to the vehicle.

If that does not solve the issue, proceed to reversing the polarity from the decoder to the bulb.

If the bulbs are still not turning on, proceed to reversing the polarity of the decoder to the vehicle's socket back to its original position.

If none of these three options solve the issue, please contact our team by live chat or email.

HID bulbs can plug into two places, and hence,the polarity can be reversed in two places:

1. From the bulb to the vehicle's socket
2. From the bulb to the ballast

Start by reversing the polarity from the bulb to the vehicle.

If that does not solve the issue, reverse the polarity from the bulb to the ballast.

If the issue is still not resolved, revert the polarity of the bulb to the vehicle to its original position.

If none of these three options solve the issue, please contact our team by live chat or email.

If you purchased decoderswith your HID bulbs, there are three connections points and hence, the polarity can be reversed in three places:

1. From the bulb to the vehicle,
2. From the bulb to the WC, and
3. From the decoder to the ballast.

Start by reversing the polarity from the bulb to the vehicle.

If that does not solve the issue, reverse the polarity from the bulb to the decoder.

If that does not solve the issue, reverse the polarity from decoder to the ballast.

If the issue is still not resolved, revert the polarity of the bulb to the vehicle to its original position.

If none of these three options solve the issue, please contact our team by live chat or email.

Flickering is generally caused by one of four things:

1. CANbus system - onboard computer not recognizing the aftermarket bulbs
2. Daytime Running Lights (DRL's)
3. Pulse Width Modulation (PWM) systems
4. Insufficient power (rare)

This is the most common reason why aftermarket LED/HID headlight bulbs flicker - the vehicle's computer system thinks there are no bulbs.

This issue can be easily solved using an LED or HID decoder.

Decoders are only required on certain vehicle makes, however, so if your make doesn't require them, the issue likely lies in one of the other three reasons mentioned above.

LED decoders are required on the following vehicle makes:

• Acura, Audi, BMW, Cadillac, Chevrolet, Chrysler, Dodge, Ford, GMC, Honda, Infiniti, Jeep, Lexus, Mercedes, Mini, Mitsubishi, RAM, Volkswagen, Volvo

HID decoders are required on the following vehicle makes:

• All vehicles years 2006 and up OR
• All Years: Acura, Audi, BMW, Cadillac, Chevrolet, Chrysler, Dodge, Ford, GMC, Honda, Infiniti, Jeep, Lexus, Mercedes, Mini, Mitsubishi, RAM, Volkswagen, Volvo

Example: A 2001 Ford F-150 will require a decoder because although it is not 2006 or newer, decoders are required on Fords for all years

This is the second most common reason why aftermarket LED/HID headlight bulbs flicker.

DRLs operate kind of like dimmer switches in the sense that when they are used during the day, the power supplied is lower and the light is less bright compared to when they are not dimmed and fully powered at night.

When the lights are dimmed, insufficient power is fed to the LEDs/HIDs, causing them to flicker.

This issue can generally be resolved by setting your light setting from automatic to manual or by disabling your DRLs.

If neither of these options solves the flickering issue or if your car does not have these options then your vehicle cannot use LEDs/HIDs and will be limited to halogen headlight bulbs.

Vehicles with PWM lighting systems are not very common but a notorious problem for aftermarket headlight bulbs.

In a PWM system, the power from the vehicle to the bulbs is supplied in pulses.

This is an issue for aftermarket LED/HID headlight bulbs since they require a constant flow of power to function.

The pulsing of the power supply causes the lights to flicker, not turn on at all, or to only work on one side.

This issue can sometimes be resolved using a specialized warning canceller but in some cases, it cannot be resolved and the vehicle will be limited to halogen headlight bulbs.

In some rare cases, very old vehicles or vehicles with old or damaged batteries will not supply enough power to the bulb, causing it to flicker. This can be resolved by getting a new battery.

When only one side does not turn on, it's usually caused by one of the components not working as it should. To help identify the broken part, you can follow these steps.

BALLASTS / DRIVERS: Swap the LED drivers or HID ballasts to the other side. If the problem is now reversed, you probably have a bad ballast.

BULBS: Swap the LED / HID bulbs to the other side. If the problem is now reversed, you probably have a bad bulb.

IGNITORS (HID Only): Swap the ignitors to the other side. If the problem is now reversed, you probably have a bad ignitor. The ignitor is the box plugged in between your ballasts and bulbs.

If none of these steps help, please check your setup for loose connections. If your vehicle has a power relay harness (HID Only), check to make sure the harness is grounded.

If you are experiencing your HID headlights working sporadically, you most likely have a power draw issue. You will need to install a power relay harness to fix the issue. Connect it directly to your vehicle's battery.

Always make sure your power relay harness is properly grounded.

If the low or high beam on your HID bi-xenon headlights is not working or inverted, it is most probably an issue with the polarity.

Make sure the connector's pins are properly aligned. You should have 3 pins on the harness (ground, low and high beam).

Release the pins and reorder them in order for the connector pins to align. This process may be repeated until you find the proper orientation for the pins.

Always make sure your power relay harness is properly grounded.