Car Stereos: radio, broken radio, kenwood radio

Question
Scott

trying to connect a Kenwood radio to one of the kids car took the broken radio out and wired the Kenwood the unit makes a noise but no sound or display checked the power wire and earth to make sure they were the right wires no power on any other wire any idea thanks

Answer
There needs to be 2 wires with power.  The constant power (yellow) and the switched power (red).  If the switched wire does not have power, the radio will not switch on.  If the constant wire does not have power, the radio will not switch on.  If they both have power, the radio should, at least, light up.  If it doesn't light up, with the power and ground wires connected and working, the radio is malfunctioning and may need to be repaired.  Hope this helps, Scott