Aftermarket head unit, how to hook up stock amp and sub???

[m1nx]

I purchased a boss bvcp9700a deck to install in my 05 sport trac adrenalin... Got the Metra 70-5519 wiring harness that includes the harness for the factory amp connection. Wired it all in and after getting past a bad ground, I came to find that the stock sub is not working. The harness has a red and white rca plug, but the deck only has a sub 1 and sub 2 option for wiring. I get feedback when I plug the white rca into either of these inputs, but the sub does not work. I tried a different deck, as my 02 escape also has the premium sound, and although I cannot adjust the subwoofer with my deck, it is functioning. So I plugged that deck into my spot trac and got the same result. Still no working sub... Any advice on how to get the stock amp and sub working with my aftermarket head unit? I mean the 6cd changer is a nice idea, but apple car play and android connect are much more ideal, and if really like to be able to use my sub with them.

Thank you so much for any help!!

 

[Mbrooks420]

I’d consider a cheap aftermarket amp. You can likely power it with the factory wiring and just add a single RCA.

 

[dvdswan]

Pictures? The pdf is for a 03 Ranger but might help since the ST is extremely close...