Stereo help on an 87

I recently replaced my stereo on my 87 with an aftermarket stereo. I installed an amp and two subs in the back also. The harness I bought from Best Buy didn't fit the stereo so I had to hook up everything myself. I am positive every wire is hooked up correctly except there are four wires that I am guessing are for amps that ran the original speakers. I hooked up just the power wire to the stereo and left those wires alone, it worked fine for a while and then all of a sudden today all of my speakers just stopped working, my amp is still working and the subs are still hitting just as hard. I'm not sure if it is a problem with the aftermarket stereo or if it has something to do with the amps I didn't hook up. Is my only option to just run new wires to all the speakers or is there a way to fix this? Any help is greatly appreciated. Thanks!

Hello
Yes there are four wires that go into the sp box. There is a small amp inside each box. Make sure you hook directly to each speeker since the wiring goes through the amp. Gerat to see that some one still has one of these cars. I am not the only one. Ha Ha

MIKE