I am making a new wiring harness for my car radio. The harness for the old factory radio has what I believe is ferrite beads on two of the 3 power wires, think it's memory wire and switched 12v. Do I need to include ferrite beads on the new harness, what wires should i put them on? Does it matter on the size/shape of the bead?
Wires for the unit are 8 x speaker wires, constant 12v, switched 12v, illumination, antenna and ground. also have aux cord at back of unit