1999.5 bose system

[VirginiaBeachA4]

i have searched and i dont know what to find. is there a way that i can go to an aftermarket stereo and use all my speakers? i have a pioneer in my car (forgot what model but its a 2009 model year). with it installed, i can only hear music out of my driver side front speaker. is there a way that i can make all four speakers work?

thanks,
chris

[ahaters46]

plug the wires into the back of the deck. If car has bose i think they are all red and tied together.