Hi All. Im new to the forum. not sure if anyone can help me. I have a 55 plate 1.6 ford focus. now everytime I turn my radio up and the bass hits the lights dim (headlights, odometer light) now this is what I have installed at present 105a brand new ford original alternator a brand new 72ah battery silver calcium ford original done the big 3 wire upgrade cleaned up the grounds in boot, headlight earth, and main earths I have a jvc head unit A FLI 900S 4 channel amp in 2 channel mode bridged with a 12" edge sub connected to it if anyone could shed any light on the situation. would be gratefully appreciated.