I'm not sure what stereo you have, but most have the amp built into them. There is one amp, but other components can cause speakers not to work. As far as the speakers, you can use aftermarket ones. That souldn't hurt anything. If you want to check wiring to the speakers, locate the speaker wires for the ones not working. Using a D cell battery, put power to the speaker through the wiring. You should hear a slight poping sound. If you do, the wiring is good.
Let me know if you have other questions.
Wednesday, January 13th, 2010 AT 10:58 PM