For Installing an aftermarket car radioWires are color coded to match you new aftermarket radio - Carxtc wiring makes your installation quicker No need to tap or cut into factory harness Match color wire to same color on new radio harness Plugs into car harness and then other end into new radio. Fits DODGE ST. REGIS 1979 to 1981 1979 1980 1981 79 80 81