Nowadays, many individuals put aftermarket HID and/or LED bulb packages in their automobiles. These kits make use of an external power booster known as a Ballast in HID installations and a Driver in LED settings. Both of these external power sources provide comparable purposes, yet they are technically extremely different. 

Furthermore, both of these goods produce RFI (Radio Frequency Interference); in fact, every electronic equipment ever produced produces RFI, although there are several varieties of this electrical interference.


When you install an LED bulb kit or a HID bulb kit in your car, you may experience greater, brighter lighting as well as AM or FM radio interference. This is defined by the fact that when you could previously pick up a radio station with the new lights installed and switched on, the same radio station is now just white noise.



A ferrite coil, sometimes known as a ferrite bead, a ferrite choke, or an RFI choke, might be the solution to your problem. These names all signify the same thing. Ferrite beads limit interference from and from devices in both directions. 

A conductive cable, such as the power supply for HID or LED lamps, works as an antenna; if the device generates radiofrequency energy, it can be sent through the cable, which acts as an accidental radiator. The bead may be necessary in this scenario to decrease RFI. In contrast, if there are other RFI sources, such as an ignition module or a battery charging alternator, The bead keeps the cable from functioning as an antenna and picking up interference from other devices. 

Ferrite coils are already in use in ordinary home applications. They may be found on USB cables, power cords for your television or home stereo, and even input power cables for your car satellite radio:



Ferrite coils are commonly used in household electronics to reduce interference signals.




LED Kits Small Ferrite Coil:

You may use a huge ferrite coil and wound the input power wires around it for an LED kit, or you can use a tiny ferrite coil and just clamp it over the power cable:


The smaller version to snap over the power wire is indicated to be roughly 1.25 x.75 x 75 inches and is ideal for RG8 or LMR400 cables. It's just the right size for the power input.

LED Kits Large Ferrite Coil:



A bigger version built for the power cables to wrap around is another alternative for an LED kit ferrite coil. The interior hole size is 0.57′′ (more than 1/2′′, 14.5 mm), which is a snug fit for RG-8 coaxial wire. This approach is superior since the power wires pass through the ferrite hole twice owing to the looping.

HID Kits Small Ferrite Coil:

For HID conversion kits, wrap a smaller ferrite choke around the ballast's power input cable as shown:


The ferrite coil should be installed around the component of the system that contains the power input to the ballast.


HID Kits Large Ferrite Coil:


For the HID kits, a bigger ferrite choke can be wrapped around the power input cable where the little wires are exposed. This helps you to properly wrap the wiring around the choke. The bigger ferrite coil is installed as follows:


A bigger version built for the power cables to wrap around is another alternative for a HID kit ferrite coil. The interior hole size is 0.57′′ (more than 1/2′′, 14.5 mm), which is a snug fit for RG-8 coaxial wire. This approach is superior since the power wires pass through the ferrite hole twice owing to the looping.

Find a part of the power input harness where the two smaller wires may wrap around and through the ferrite coil to make a loop.

Sources for Ferrite coils:
Large style designed for looping wires around coil: RND-6 ( Wurtz number 7427151 ) snap-on chokes
The inside hole size is 0.57″ (over 1/2″, 14.5 mm)

Small style designed to snap onto power input cable: RCT2 RFI Radio Frequency Interference Ferrite Chokes – Black
measures approximately 1.25 x .75 x 75 inches

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