[NA] New headlights = radio fuzz

CJones

CJones

Final Approach
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I replaced the stock Halogen headlights with LED headlights in my 03 Jeep Wrangler. Now I seem to have some fuzz in my radio when the lights are turned on. It's not a direct buzz that changes with RPM like a bad ground - it just seems to interfere with the FM radio reception a bit.

I didn't run any new wires for the headlights - they plug into the factory harness other than a couple of 'piggy back' connections to the running lights and turn signals.

Should I put some sort of filter on the radio power or it it just a side effect of putting more 'modern' lights in an older style electrical (stock radio) system?
 
Radio interference with LED lights is a known issue. I ran into it with my garage opener.
 
I saw something about putting ferrite clips on the power lines. I'll give that a try.
 
CJones said:
Should I put some sort of filter on the radio power or it it just a side effect of putting more 'modern' lights in an older style electrical (stock radio) system?
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CJones said:
I saw something about putting ferrite clips on the power lines. I'll give that a try.
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Usually it's better to fix the EMI at the source. I would try the ferrites at the headlight wires first, as close as possible to the lights. Most likely the EMI is getting radiated by the headlight wiring and getting into the radio antenna, not getting in via the radio's power lines.
Are the LEDs aftermarket or OEM? OEM is far more likely to have filtering built in, albeit at several times the price.
 
flyingbrit said:
Usually it's better to fix the EMI at the source. I would try the ferrites at the headlight wires first, as close as possible to the lights. Most likely the EMI is getting radiated by the headlight wiring and getting into the radio antenna, not getting in via the radio's power lines.
Are the LEDs aftermarket or OEM? OEM is far more likely to have filtering built in, albeit at several times the price.
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Yeah.... these are $80 Amazon specials, so I'm not really surprised that they aren't super high quality, but still would like to try to reduce it as much as possible. OTOH, maybe I can justify upgrading the stock radio to something with bluetooth and kiss FM commercial land goodbye.
 
flyingbrit said:
Usually it's better to fix the EMI at the source. I would try the ferrites at the headlight wires first, as close as possible to the lights. Most likely the EMI is getting radiated by the headlight wiring and getting into the radio antenna, not getting in via the radio's power lines.
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Exactly. Fix a problem at the source, rather than the victim. That way you solve more problems. And I agree that the likely path is what is described above. Noise from the lights is radiating and being picked up by the radio antenna.

Oh, and I'm not just saying that, I've been an EMC engineer by profession for 44 years, so it's what I did when I worked in industry and now work on a few national and international standards committees on the subject while basically being retired from industry.
 
Ghery said:
Exactly. Fix a problem at the source, rather than the victim. That way you solve more problems. And I agree that the likely path is what is described above. Noise from the lights is radiating and being picked up by the radio antenna.

Oh, and I'm not just saying that, I've been an EMC engineer by profession for 44 years, so it's what I did when I worked in industry and now work on a few national and international standards committees on the subject while basically being retired from industry.
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I agree completely. However, in this instance, I paid $80 for a pair of LED headlights, so I get what I pay for. They're also sealed as far as I can tell, so not sure how easy it would be to get inside and tinker with transformers, etc. Secondly it's in a 2003 Jeep Wrangler, so a fuzzy radio basically just adds to the ambiance, right? I did get the ferrite clips in yesterday, but haven't had a chance to tinker with them yet.
 
CJones said:
I agree completely. However, in this instance, I paid $80 for a pair of LED headlights, so I get what I pay for. They're also sealed as far as I can tell, so not sure how easy it would be to get inside and tinker with transformers, etc. Secondly it's in a 2003 Jeep Wrangler, so a fuzzy radio basically just adds to the ambiance, right? I did get the ferrite clips in yesterday, but haven't had a chance to tinker with them yet.
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You've got a newer Wrangler than mine. It's a 1999 TJ. :p

Yes, the headlights are probably sealed. If the ferrites are the right mix they might help. As low in frequency as the AM band is, you might have a challenge on your hands. If you have a large enough opening in the ferrites when they are closed, and enough wire in the harness, try wrapping the ferrite a couple times to see if that helps further.
 
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