Radio Scrambles when I turn lights on

[RichLo]

On my snow-plow truck I added some cheap ebay LED lights to the front and back for night time plowing and whenever I use them the radio turns to fuzz. I'm wondering if there's something cheap and easy that I can do to fix this?

Worth noting too that it has 2 batteries, 2 alternators and plenty of additional ground cables. It holds 14v even during the heaviest electrical use.

 

[df2x4]

You're not the first person I've seen have this problem. Apparently it's a fairly common issue with cheaper LEDs, they lack the proper shielding to prevent them from interfering with radio equipment. Unfortunately I'm not sure of a way to solve it without replacing them.

 

[delta_p]

If the bulb has a wire coming out that has the plug, you could try to add a clip on ferrite bead to act as an RF choke. If the wire is long enough you could loop it through twice or more and get more choking. The DC-DC switching of the LED driver is probably getting onto the wire and acting like an antenna and your car antenna is receiving it. If the hash is not that strong you might be able to cut it some by choking like this.

 

[RichLo]

Thats interesting, I just googled ferrite bead. Ive never heard of those before, which wire do you think needs it the most? Neg coming out of light, pos going into light, or pos coming from relay (I have multiple lights coming from each relay)?

I might just order a bulk pack and start clipping them on to see if they help.

 

[delta_p]

You'd just have to try them all really. And put it right as close to the light as possible. The LED driver uses inductors (wire coil) that it either steps up the DC voltage or steps down the DC voltage to drive the LED's. You can google "buck converter" and "boost converter". There's probably two inductors in their and their being switched between. When the coils turn off you get the voltage kick that RFI (like a coil in ignition throwing a spark gap). It's probably what's causing the hash and some is getting on the wire and some is just due to crappy shielding like df2X4 said. It's a hit an miss with the beads but it just might work or cut it down.

 

[Ehall8702]

To OP, get these will fix ur issue. Put a coil on each led bulb wire, double wire through coil if long enuff. I have been using cheap LEDs for years and I don't really use FM in my vehicles but first time I did I heard the "bzzzzzz". Been using these ever since and putting them on my coustumers cars too


https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/173298698895

 

[RichLo]

I just ordered them, Thanks everybody! I'll be sure to update this thread whether they work or not.

 

[df2x4]

I'm curious to see the result. I've seen the ferrite beads before but never considered them for this.