Help! LEad Light bar causing RF Interference

Every time I turn my light bar on my stereo loses all reception. I played with grounds to no improvement. Google search revealed that LED lights actually
Create large EMI fields that kill radio reception. How do I cure this?? Half the time I listen to the stereo I want the light bar on at night…. Right now I have a stranded 12ga wire shoved in the female antenna port and about 12′ of wires looped back and forth under the dash. Works great without light bar. Any ideas??