On my 2004 Durango I used the dash cigarette lighter to tap into.
Needed it to install an after market stereo.  It's proximity to the
stereo made it very simple to tap.

Thanks again - that's the info I was looking for.  You just made my
life MUCH easier tomorrow.

The Dk. Blue wire will be in a harness with about 6 others.  I will be
bundled with the yellow wire I referenced.  This Dk. Blue is your Ignition 1
wire and will only have 12 volts when you have the key all the way forward
(with or with out the truck running)  it will not work in the accessory
position.

If you want it to work in the accessory position, then you have to tap your
accessory wire which is Green or Orange.

Ok, so the Dark Blue would be a 12v source that goes off with the
ignition?   I pulled the lower panel (I assume what you mean when you
say knee bolster) - will this Dark Blue wire be with many others, or
by itself (or only a few others)?  

Thanks!

Easiest would be to tap to your ignition or starter wire.  You can find this
in the main harness running from the ignition switch down.  Drop the knee
bolster, find the harness and you want the Dark Blue for your ignition or
Yellow for your starter.

I'm looking for a 12v power source on the driver's side - one that
goes off with the key.   Is there an easy spot to do this or will I
have to run one in from the fuse box in the engine compartment?