1999 Chevy Corvette Turn Signals Causing Static on AM/FM

Electrical problem
1999 Chevy Corvette V8 Two Wheel Drive Automatic

Over the past month, I've added LED Lights in various locations of my C5. I "tapped into" wiring for the "Under the Hood Light; both front and rear turn signals, into the Footwell Light wires, and into the Fog Light wires. All LED Lights and remaining OEM Lights work fine. Yesterday, I turned on the AM/FM Raido and found "static" in sync with the turn signals was coming through the Radio, both AM & FM; no static with turn signal on heard when CD Player was on. Naturally, when I removed the fuse for the turn signals, the AM/FM Raido worked fine. Next, I revmoved the fuses for the footwell, under-the-hood lights, and Fog Lights but there was still static through the Radio, generated by the turn signals. It could be a "grounding problem" but how do I tell where the "grounding problem" is located? If you don't think it's "poor grounding" generating the static, what do you supsect and that I should check? Thanks