OK, I wired up the head unit (I got the optional harness with the connector to turn on the amp, which is connected to the blue ant/amp wire from the radio. I don't get any sound. I checked the amp fuse under the hood and it seemed OK. Even so, I tried another fuse in it, just in case and it still doesn't work. I noticed that the factory radio sounded very weak/tinny. Is it possible that my factory amp is blown? If so, why would I get sound from the factory radio and none from the aftermarket one? Another question would be is the amp turn on wire always the pink one or could it be one of the other wires in the secondary factory harness?