I am helping a friend put in his new head unit, but we have hit a brick wall. Let me first give some history so you have some background on the car.
Originally he had a old Pioneer radio that was stolen out of his car, the dash was ripped up, etc. Now I am trying to get his current head unit to work, Kenwood kdc mp425, but we have ran into a rather huge problem. The head unit was ordered from Crutchfield, along with the wiring harness and instructions. The first one we wired it up and had no power to the unit, it wouldn't turn on. I double and triple checked the 12V constant (always hot) and 12V ignition wires (hot when key is on) and all the fuses, including thorough inspection of the fuse for the radio.
I called Crutchfield for support and he suggested that I touch the power and ground wires to the battery, which we did and it still wouldn't turn on. He said the head unit was bad and I also couldn't think of another reason that it wouldn't turn on besides the head unit being bad. So we sent it back in exchange for another head unit.
Now, assuming that the new head unit was good, we hooked up the wiring harness and this head unit would not turn on. So before I try everything again, I'm looking for some help. I have a idea to put the ground wire on the chasis somewhere rather than in the harness, where there is a spot for it. I was also thinking that something happened to the wires when the old unit was stolen, but the constant and ignition wires are hot? Maybe there is something special with the Kenwood's I dont know about?
Thanks.