i have just set up my sons new entertainment unit cd/dvd player with amp , subwoofers , parcel shelf speakers , lcd monitor. to cut a long story short every thing was working fine until i stated to install a led switch to work his neons , since then the speaker make a hum sound , when you switch any items ie neon lights , car indicators etc you hear the noise not sure if it is coming from the speakers or the amp , tried taken every thing back the way it was but still hett ing all the sounds
You've probably got a connection touching metal in the car and grounding out. Double-check all the spots you touched when you installed that switch and be sure everything has clearance.