hey guys im new to this forum after purchasing a new company van. its a 07 astravan 1.7cdti sportive. the insurance on a 1.9 was too much. i recently put a new headunit it. which i need to swap the yellow and red cables around because it aint stroing anything an is a pain in the bum. the other problem im having is my amp wont switch on. the fuses havnt blown so im thinking is it the earth cable as all the other cables are attached and ok. please help guys!!