I have a 2003 Mitsubishi Outlander XLS. I'm trying to hook up my system. I hooked up my aftermarket stereo and I had to buy the harness because my car has a factory amp under the drivers seat. I hooked it up and my stereo turns on but the factory amp isn't getting any power because the speakers don't work. I hooked the blue to blue wire and it doesn't come on. I know it's the power because my friend ran a power wire to my battery and hooked it up to the power wire to the harness and the speakers turned on. I kept it like that but my battery died like 3 weeks later. When I turned my car off, it didn't turn off my factory amp. I want to hook up my subs and aftermarket amp but I'm stuck on this problem. What should I do?
