So I'm collecting my parts for my 1990 4runner system. I have an alpine KTP-445 4ch for the speakers, going to probably use an alpine CDA-105 for ease of intergration with the 4ch, and a kenwood 9105d for my 10". I have some polk audio 4" speakers to drop in the front then I'm looking to do some polk audio or alpine 5.25s in the rear. What all is involved to bypass the rear speaker amps? There must be some kind of signal wire running to them for the amp, I could just remove the amp then hook the signal wires up to the new speakers, correct? Then hook up the outputs for the 4 channel up behind my dash. In case no one knew, the ktp-445 uses the power from the wiring harness for the factory radio, on the box it says its fine to hook it up that way if the factory radio has a 15 amp circuit. I just checked and my 1990 has a 7.5 amp fuse, but I haven't had the dash apart yet to check the gauge of the power wires. Does anyone know what size they are? If it's at least 18 gauge then I was just going to put a 15 amp fuse in the fuse box.