Good morning fellow A/V enthusiasts. I have been researching upgrades for my wife's car and I couldn't seem to find an answer to this exact question. Or I just don't have enough understanding of the field.

So here goes, Dodge Journey 8.4N alpine system with factory amp and subwoofer. The head unit (keeping for controling heated seats, heated steering wheel etc. Would like to go from there to LC2i pro, which I would use just for the subwoofer line. Then add a mono amp and 12" sub in the back.

Can I take the rest of the speakers wires and hook them back up to the factory amp for power? Or will this cause issues? The factory amp seems to use a plug for everything and not just speakers to a terminal. Any information would be greatly appreciated.