Radio makes loud *tick* noise when turn volume off or change station.?

Everytime I change the radio station or turn my volume all the way down it makes a loud *tick* noise on my car stereo as well as recent engine wine, I recently installed a 4 channel amp and another set of rca wires they are triple insulated american accesories with a ground on each end, I have both vocal rcas running along the penger side of the car could this be my problem? Is american accessories junk? Do I have a wire grounded out somewere? Although my systems real clean terminals heat shrink etc. Would appreciate any help.