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LED lights on excavator totally disrupts the stereo system.

fastline

Member
I decided to replace all the halogen lighting on an excavator with LED. It became obvious at first test that the pulsed drivers in the LEDs are causing major interference with the audio system. Not that this is a 'huge' deal as the machine is not used much in the dark and usually when operating a 56k lb machine in the dark, you want to be on point, not jamming...lol

It would be nice to solve the issue if easy enough. I ran into this years ago with a vehicle aftermarket system and a group loop isolator took care of it. In the case of the excavator, two lights are on the cab which are about 3ft from the stereo antenna. I also believe the cab is somewhat isolated sitting on rubber pads. I unplugged the two on the cab and the problem was 90% resolved but still a little noise.

Just curious if you guys have run into this? I am trying to figure out how the noise it getting to the stereo first of all. Through chassis ground? sharing a power wire? To shake this up more I do believe the stereo is 12V in this 24V system and there is a small power converter in the cab that makes the 12V just for that. I am also wondering if the noise is being "heard" just by the antenna? It is pretty obvious, we go from hearing music to bam, nothing but white noise or similar. Just static, not even a hint of music. Turn lights off, back to normal........

Or do we call this a "safety feature"???? lmao....
 

audioguru

Well-Known Member
Most Helpful Member
The pulsing might be used for dimming the LEDs or for limiting the average current of the LEDs with a little amount of heating.
The pulsing circuit can be replaced by huge, expensive and very hot variable resistors with a substantial amount of power wasted.

If the noise is picked up by the radio's antenna then the radio will play the noise if it is set to receive AM, not FM.
An AM radio picks up all kinds and lots of interference. An FM radio designed correctly ignores and does not play interference.
 

Diver300

Well-Known Member
Most Helpful Member
Have you got a link to the lights?

Many LED lights will run on 12 or 24 V, and they often achieve that with a buck converter. https://en.wikipedia.org/wiki/Buck_converter

One problem with buck converters is that the current they take from the supply isn't steady, and it turns on and off all the time, at 20 kHz or more. That switching can cause interference with the rest of the vehicle, because the current is varying all the time.

There are various things that you could try:-
- connecting capacitors in parallel with the supply as close to the light as possible
- insert a filter in series with the supply to the light.
- have wires for both the +ve and the -ve of the light going all the way back to the battery, and twist those wires together along their entire length

Other LED lights work with a simple resistor or with a current regulator. Those are less efficient, so produce more heat, than buck converters, and often have to be specified for either 12 V or 24 V, but there is virtually no electrical noise from circuits like that.

I have seen LED lights that work from either 12 V or 24 V without using a high frequency converter. The assembly was basically two 12 V lights run in parallel, and there was an electronic switch to put them in parallel if the voltage was over about 18 V.
 

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