kenwood dnx7180, using metra kit

it also says this about the mute wire from the metra harness on page 9 "Connect the Brown wire to the mute wire of the aftermarket radio. If the aftermarket radio does not have a Mute wire, tape up the Brown wire. NOTE: If the radio shuts off when OnStar is activated even though the Mute wire is connected, you may need to add a resistor between the switched 12V wire and the mute line. We suggest 10K ohms. If the radio still shuts off, you may want to reduce the resistor value."If the radio mutes at inappropriate times (such as when the lights are switched on or off), the resistor value may need to be increased

just as a test for your installer to do i would disconnect the mute and SWC wires from the kenwood and see if that does anything. guessing at the problem can only go so far before you just need to start unhooking things to see exactly what the cause is. if you unhook those wires and the problem continues then you have something defective for sure. and also i just realized that there are two brown wires on the metra harness. one is the mute and the other is to connect to the steering wheel control of the kenwood so maybe there is something going on there too?...