Tower lights making noise in the radio...Help!!!!?

I put a 7 light bar on my tower.Wired it up with two 40amp relays..I grounded the lights to the light bar and and then grounded the bar to the batery.When I turn my radio on a terrible squeal comes from the speakers.The only way to make it stop is to unground the lights from the battery.The lights are wired for power directly from the battery.Did I ground it right or something im missing.The lights work fine.I just cant play the radio right now....Do I need to ground each light seperatly?Please I need help becuase I unhooked them until I figure out the problem.

you don't need to ground each light seperatly, but you do need to ground the lights right to the battery, do not use the tower as a path back to the battery. If you want diagrams and pics check out www.diytower.com