Is it possible to upgrade the amplifyer and subwoofer in a 2003 Ford Expedition with the optional subwoofer? I would like to retain the stock appearance and not have to cut the interior of the vehilce up. I have heard that the factory stereo puts out a silly amount of ohms wich make aftermarket amplifyers not compatible.

 

take a voltmeter and check the ohms. thatll tell you if u need to start with a new head unit or if a new amp will work