Red is battery. some have two red wires, but they are both battery(12 volts). it is a switchable 12 volts which means it comes on when you start car. yellow is a constant 12 volts. it is for memory. blue is for power antenna(ive never used it. i keep blue wire disconnected) then you have the set of colored wires like green and gray stripe. those are speaker wires. match it with its other color coded wire. example.....brown with yellow stripe wire goes with the brown wire to connect speaker. enjoy