Well, I'm sure the noise is being generated by the high frequency and high voltage interfering with the radio waves. I was a certified welder and anytime we used the TIG method (now GTAW), which uses high frequency, high voltage, the radio reception in the shop was crap. Everything was properly grounded. We'll see what happens when I install the relay kit. If nothing happens, I'll try grounding the ballast cases. Yes, they are metal.