Recently I decided to upgrade my car's audio equipment so I bought a new stereo deck, a 1100 watt amplifier and a 800 watt subwoofer. With a few friends we went about setting it up and we have everything connected correctly according to multiple diagrams. The wires have been connected and re-connected to check for shorts. Every time I turn on the car however the "protection" light on the amp lights up which says in the manual is caused by faulty wiring. No matter what I do I can't seem to get this to work. What is going wrong??