Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Installed h11 leds in foglights; now have bad radio interference. Any suggestions to fix this?

Had these ordered from amazon and installed them in my 13 crv foglights.
CAR ROVER H11 LED Headlight Bulbs, Fanless 6500K 8000 Lumens Extremely Bright H8 H9 1860 Chips Conversion Kit
Was driving at night with them and now my radio frequencies below 106FM have basically gone to nothing. Any solutions? I contacted the company and they are going to send me a decoder to put on the lights but would that fix this? I also ordered some ferrite chokes to see if that might null some of these frequency issues. Any and all suggestions are welcomed. I want to try and keep these bulbs. Definitely better than trying to use the less-bright 1/2k lumen bulbs.

Go back to stock bulbs.


I have never understood what possess people to try to out-engineer the people that engineered the vehicle?


1 Like

The ferrites might help, but I expect won’t solve the problem entirely. What’s going on is that LED’s require lower voltages than regular light bulbs. To get reduce the battery voltage to what the LED wants there’s a circuit that sort of works similar to how you’d regulate the flow of water from a garden hose you want if all you could do is turn it either full on or full off. You’d turn it on and off rapidly and vary the “on” time to get the flow you wanted. that’s what’s happening with your new bulbs, and your radio is hearing the turning on/turning off current transitions as radio frequency interference. Whether the ferrites will work at all depends on whether the entry point is the radio antenna, where it won’t work, or at the power supply input to the radio, where it might work or at least help.


Where would you suggest I try to add on the ferrites? There’s only so much wiring to clip into that’s reachable for the foglights. Or should I try hooking them onto somewhere else in the wiring for the car?
Plus, do you think the decoders for the bulbs would make any difference if I have those on both bulbs?

I have no idea where to try the ferrites or what the decoder even does. I had a problem with rfi interference making my fm radio hiss at home, and I didn’t have any ferrites on hand. I used nails instead, wrapping the wires around the nail a dozen times or so which were powering the various gadgets near the radio, CD player, mp3 player, a clock radio, etc and including the radio power wire too. It definitely helped. But I still have to have the radio fm antenna at just the right angle. And not step on the nails in my bare feet :wink:

You’re talking about an incredibly complicated solution to a very simple problem.

The bulbs you installed do not work properly in your car. They are faulty. Replace them with a type of bulb that will work properly in your car.

After all, this is just for show. The lamps your car came with are more than enough to see properly.


it makes noise on radio with lights off? or only when on? i would say leave them off.

Since fog lights are now basically a fashion statement. Put the stock bulbs back in. Just as an aside, if you need the fogs just because it is night, you may also need your vision checked.

1 Like

It’s only when the fog lights are on. I tried with the regular lights on and it doesn’t change anything. Once you flip the fog lights on, it starts hissing. And I know some people have talked about how it shouldn’t be about the distance being an issue and etc, I just want the extra illumination from these and the bulbs actually do a good job with that.

Did you check to see if there are brighter options available in the stock bulbs?

They only have the same or minimal halogen brightness. I prefer the LEDs because they draw less power and don’t tax the battery as much plus the instant on/off is nice. I just wish they had ones that didn’t go all haywire. There’s always the pro/con with stuff like this.

You have three choices:

  1. enjoy the extra illumination and live with the radio noise
  2. eliminate the extra illumination and enjoy the radio.
  3. spend lots of time and money trying to fix the problem you caused when you installed the bulb - efforts which may or may not be successful.

If it were me, I’d go with 2, because good illumination is what headlights are for. Fog lamps are for seeing the road when it’s foggy, and tangentially for increasing your visibility to others in bad weather. Nothing more. The stock bulbs will perform this function just fine.

If I insisted on keeping the LEDs, I’d be looking into encapsulating the LED bulbs in a Faraday cage, but searching for info on that is annoying because of all the blogs from survival fetishists putting LED flashlights in Faraday cages so that they will survive “The Big One™”

On and off between the regular bulbs and these problem causing LED’s is almost nothing. Taxing the battery , not enough to even worry about. Besides just how often do you need fog lights anyway.

Are these the ones you bought?

Those are headlamps not fog lights.
This has to be the most ironic statement in the description-

Most important, No radio interference,

I would return them if they are actually causing interference. Maybe they are defective or just poorly designed. Either way, not something you should have to modify your car to accept. BTW, the noise could be radiated, or it may be conducted. The solution to either is different…

There is actually a recent advisory from the US Coast Guard regarding VHF radio interference caused by LEDs so this is a well-known problem. However, since you are also having the problem with halogen bulbs, the LEDs aren’t the problem. Check the antenna lead and plug.

No I purposefully chose to put these bulbs in the foglights BECAUSE they were far brighter than what a typical “foglight” bulb offered. I had another pair of LEDs that I used I believe from JDM ASTAR but they really were no better than the halogens in terms of brightness. These actually project better in the housing. I know because of every car, only certain bulbs actually are first, brighter than a stock bulb, and second, actually work well with the car’s reflector housing to truly ‘throw’ the light. When I tried these bulbs, they worked really well but the radio interference only became an issue recently that has become worse.
And @NYBo I never had radio issues with the stock halogens, it’s juat they totally suck at putting out light, hence the efforts to upgrade the bulbs and put LEDs in them.

Ah, I misunderstood. Yep, the LEDs are the likely cause.

I installed a set of Sylvania SilverStar zXe bulbs in my fog lights. Incredibly bright without the obnoxious blue tint often seen in bright bulbs. Something to consider if the solution from the LED manufacturer doesn’t work.

Of course they are because they are HEADLIGHTS.
If the vehicle manufacturer intended the car to have two sets of headlamps, that’s how they would be designed.
Are you even sure the fog lamp wiring is capable of handling the power demand of these headlamps?

Why don’t you put in LED versions of the fog lights, actually designed for the intended purpose?

H11 bulbs are used in both headlights and fog lights. This is from the link you provided:

LEDs will draw less current than comparable halogens every time.