Audio Systems: Need help with car audio., eagle talon tsi, rca cables

Question
I have a 1996 Eagle Talon Tsi AWD Turbo. I bought the car with an aftermarket VR3 stereo. I disconnected the battery so I could remove the radio and install an amplifier for a subwoofer which I have done with several other cars. When I hooked the radio back up and put everything back together I went and reconnected the battery cable. I heard a series of clicks and immediately disconnected the cable. I had realized I had reconnected the batter with the key on accessory (to move the shifter nob). I turned the key off and removed it. I reconnected the battery and the car started fine but as I drove the speakers produced a humm that changed pitch with the RPM's of the car. It was strange. So I tore everything apart again and checked all of the fuses. They were all fine, as per my fuse checking thing. Yet somehow the radio just would not turn on and just made a buzzing over the radio. I removed the radio and installed another one. and it would not turn on either. I don't know what is wrong. I was thinking about taking it up to a shop and having them fix the wiring mess I discovered (grounded to a piece of metal in the cabin of the car, parking brake wire clipped onto the parking brake wire in which is disconnected, audio wires taped off and rca cables running to stock speakers with no amplifier, Reverse wire tapped in with constant wire, etc.)

Answer
I think you have reversed the wires going to the head unit.  One is constant 12v and stays on all the time. The other is the remote turn-on coming from the ignition switch. Is it possible you got them reversed?  If so, it would do what you have described, I think.

Check that out and see if it helps.

Another thing you can try is just to bypass all power wiring and run a couple of separate lines directly from battery to the unit and power it up.  See what happens.  Also, check the ground line carefully; it must be a good, solid, metal to metal surface ground - if not a good ground it can bring in the buzz that you talked about, too.

Let me know if you need more.