2003 Ford Mustang Car Stereo Wiring Diagram - MODIFIEDLIFE 2003 Ford Mustang Car Stereo Wiring Diagram Whether your an expert installer or a novice enthusiast with a 2003 Ford Mustang, an automotive wiring diagram can save yourself time and headaches. One of the most time consuming tasks with installing a car stereo, car radio, car speakers, car amplifier, car navigation or any mobile electronics is identifying the correct wires for a 2003 Ford Mustang. 2003 Mustang Radio Wiring Diagram | Free Wiring Diagram Variety of 2003 mustang radio wiring diagram. A wiring diagram is a streamlined traditional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified forms, and the power and also signal links in between the gadgets.