Depending on how far you want to go with this the best way to do it is to run new speaker wires as well as a dedicated power line for the amplifier. Now if you are not planning on upgrading the stereo H/U there are adapter plugs available at Crutchfield.
Not sure how far they go for powering up a amp etc. Look them up online and see if there is a plug adapter for the application. I am sure you will have to bring in a power supply for it but there should be a plug assembly for the speakers that will connect to the amp outputs.
Me I strip the interior down to the sheet metal and start from scratch.
A little food for thought.............gotta be a easier way
I have a Nak CD700II that is going up for sale on ebay but its not a cheap unit.
2006 F250 LARIAT CCSB 4X4
ARP Studs, O-Ringed Heads
X4 PHP 65 HP Custom Tow Tune
Atlas40 or Atlas80 Ficm Tune
CAT EC-1 Coolant, IPR Coolant filter
BPD Waterpump, BPD way of thinking
Fass-125 to a Adjustable Pressure Reg.
Turbo-back SS 4" pipe, Corsa Muffler -7" Tip
6.4 starter, DC Power 270 amp alt
Die Hard Platinum AGM all 2/0 Cables
Fabtech Radius Arms
7" lift w: Icon Progressive Coil Springs
2008 up Carli/Deaver rear springs
All riding on some Fatty-Daddy 38/15.50/18 Toyo's
Last edited by mhatlen; 09-22-2016 at 04:05 PM.