I'm hoping some of the gurus here can help me out. Right now I have the 2004 EX double din HU along with and aftermarket Kenwood satelite tuner running thru an FM modulator. The satelite tuner and modulator are taking power (12V switch and constant) from the radio power leads. I am in the middle of installing a 9" overhead DVD system along with a 6" monitor for the front passenger. Both of these video devices also needs 12V constant and switch power sources. Where should I tap into for these additional devices. I was going to tap into the same radio power wires, but it dawned on me that this probably would overload that circuit. Where should I tap next?

You're right to be concerned here. Good thinking. :)

A basic way to see how concerned you need to be is to add up the power fuses of all of the devices you want to hook up. This is the maximum current draw you have to allow for. In practice, your pieces will draw less current than this but by allowing for this much current draw, you'll have a nice margin of safety.

The ignition wires are no problem. They draw milliamps of current. It's the constant power wires you have to worry about. If it was me, I'd go straight to the battery through the firewall, setting up a distribution inside the vehicle for all of your devices. Here's a thread (http://www.elementownersclub.com/forums/showthread.php?t=19524&highlight=wire+firewall) as to how to do this.

Somebody else may have a simpler solution for you.