My Alpine ILX-W650 has 4V preamp signals and it pushes the factory amp pretty good. However I feel that by splicing the factory connector B with wire taps and not utilizing the Metra Metra 70-1731, I made a poor decision by risking sub-par connections. I am thinking of removing all the taps and using the harness instead, but now that means ill have a bunch of exposed wire where the taps were that I need to somehow seal up.Two things to note:
Just a reminder the "shark fin" antenna has a signal booster so be sure to connect the "power antenna" wire from the head unit to the wire blue on the "Metra 40-HD10 Antenna Adapter", otherwise you don't get much radio reception.
The head unit I installed outputs 2V preamp signals and sounds as good as factory.
Did you manage to figure out the backup camera hookup yet? I cannot get my backup camera to power on from the reverse lamp.