How to Remove Radio Interference Using Ferrite Coils for HID and LED Headlights

Many people nowadays are installing aftermarket HID and/or LED conversion kits in their headlights and fog lights. These new conversion kits use an external power booster, called a Ballast for HID setups and a Driver for LED setups. Both of these external power supplies do similar functions, but technically they are quite different. Also, both of these products create RFI (Radio Frequency Interference); in fact every electronic device ever made creates RFI, but there are different types of this electrical interference. Sometimes when installing an LED conversion kit or an HID conversion kit in your vehicle the result can be better, brighter light, but also a side effect of AM or FM radio interference. This is characterized by where you once were able to pick up a radio station, with the new lights installed and turned on, now that same radio station is just white noise.

Here is an example of a DIY ferrite coil that can be used in lighting installs.

Here is an example of a DIY ferrite coil that can be used in lighting installs.

The solution for your problem might be what is called a ferrite coil, also known as a ferrite bead, a ferrite choke, or an RFI choke. All of these names mean the same thing. Ferrite beads prevent interference in two directions: from a device or to a device. A conductive cable such as the input power for the HID or LED headlight bulbs acts as an antenna – if the device produces radio frequency energy, this can be transmitted through the cable, which acts as an unintentional radiator. In this case the bead may be required to reduce RFI. Conversely, if there are other sources of RFI, such as an ignition module or battery charging alternator, the bead prevents the cable from acting as an antenna and receiving interference from these other devices.

Ferrite coils are already used in everyday household uses. You can find them on USB cables, power cords for your television or home stereo, and even on input power cables on your automotive satellite radio:

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

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

LED Conversion Kits Small Ferrite Coil:

For an LED Headlight conversion kit you can use a large ferrite coil and wind the input power wires around it, or you can use a small ferrite coil, and just clamp it over the power cable:

LED Conversion Kits Large Ferrite Coil:


HID Conversion Kits Small Ferrite Coil:

For the HID conversion kits you can put a smaller ferrite choke around the power input cable of the ballast like this:

HID Conversion Kits Large Ferrite Coil:

For the HID conversion kits you can put a larger ferrite choke around the power input cable where the small wires are exposed. This allows you to wrap the wiring around the choke for a better result. This is how to install the larger ferrite coil:

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

Custom Hot Rod – 1971 Montgomery Ward T555 Trail Master Trike Build

Montgomery Ward T555 Trail Master Three Wheeler Trike

Montgomery Ward T555 Trail Master Three Wheeler Trike

Everybody has probably seen a Montgomery Ward 3 wheeler, but had no idea it was called a T555 (pronounced Tee Five Fifty Five) and also nicknamed the Trail Master. These things can be found at any antique show, your grandpa’s shed buried under old blankets and sawdust, or on your parent’s home videos from the 70’s. These were produced by Montgomery Ward in Omaha, Nebraska in the early 1970’s and were all built by hand. Only a few are left in operation today and from time to time you can find one that was restored and able to be ridden today.

This is what most of these 3 wheeled death traps look like nowadays.

This is what most of these 3 wheeled death traps look like nowadays.

I got a hold of one of these things, found in an older gentleman’s garage – hadn’t been touched in decades, and I fell in love with it! There was just something about the American nostalgia about it, and the cool shape and design, knowing it was hand-built 40 years ago by Montgomery Ward, I just had to have it – and I had to fix it up! Like most vehicles that I own I can’t just leave them stock, I had to customize it and make it mine.

We started with the frame: Moved the seat back 5 inches, and removed the flange in the middle of the frame in front of the seat. We had the whole thing powdercoated a metallic black, and the front fender and foot-wells were coated in Line-x bed coating for durability. The wheels were also taken apart and powdercoated silver to match some other components on the engine.

Next we had a new seat made out of waterproof vinyl by a local upholstery shop, took the engine apart, powdercoated the cover panels and ordered a bunch of new drivetrain parts. We got all new bearings, new brakes (custom made lines), new twist-throttle handlebar grips, a new brake handle, built a custom battery box for a Vision X battery and built a wildly custom intake an exhaust using a K&N filter, and a custom mini-bike style exhaust muffler. Everything got the presidential treatment! No expense was spared, and the whole project probably cost me about $5K with buying the trike, new parts, powdercoating, custom fabricating, and other labor.

We actually found an updated engine from a 1980’s snowblower to use instead of the original one, but it was still the Tecumseh HM80 used to power this American Made beast! The reason for going with the newer engine was not that the original was worn out, but the new one had less antiquated electronics controlling the ignition and came with a built in electric-start for use with a 110v extension cord! We thought about upgrading to a 10hp engine, but thought we should at least keep the engine original-ish.

On the front of the T555 trike we did all kinds of stuff there too. We found some motorcycle handlebar grips that had a really cool Harley/hot rod look to them, pointed on the ends, and an integrated twist-style throttle. Also, we tossed the original two-handle brake levers and installed a brand new single lever brake handle, with all new brake pads, and all new cables which had to be custom made. Also mounted on the handle bar is a Vision X LED Light bar and a dirt-bike style ignition kill switch.

The original headlight on this thing was a 4.5″ round halogen incandescent lamp that was actually routed through the wiring as part of the ignition circuit. We pulled it off and installed a direct replacement (same brand as the original also) JW Speaker brand 6045 LED headlight. JW Speaker still even had the rubber retaining rings in stock to hold it in place so we were even able to use the stock headlight bucket.


The finishing touches on this trike was a set of red LED driving lights mounted to the rear of the truck, activated on the same circuit as the headlight. We used a pair of GTR Lighting 7″ long LED Lightning strips because they are super low profile (don’t really even notice them when off), and they are waterproof, and insanely bright!

GMC Canyon Roof Mounted LED Light Bar

If you have a GMC Canyon or Chevy Colorado, and you want to put a roof-mounted light bar on it you’ve probably found that nobody makes a vehicle specific kit. A friend of mine wanted to add this type of Light Bar setup to his 2007 Canyon and I found a product that actually works really good!

Canyon LED Roof Mount Light Bar

You’ll need these items to make it work (Click the links to see each part):

For this installation we actually installed Nut-Certs into the roof, drilled a hole through the roof for the wiring to go through, and used stainless steel cap bolts from the hardware store. All I wanted to help with was to show pictures that it can be done, show you what size light bar to use, and some pictures to give you an idea of how it all goes together.

We used the Vision X brand XIL-801 Flood Beam LED Light bar, it’s 42″ long and fit perfectly on the roof of this Canyon. We got all of the parts to do this install from Headlight Revolution, so if you want to replicate this install contact Headlight Revolution at this link: HERE.