I used 5 wires and 4 RCA's from the SOS harness on my 2005 NSX. It has been working just fine for the past 4 years.
Black = ground
Red = Switched
Yellow = Constant
Orange = Illumination (your screen will dim when you turn the lights on like the OEM radio
Blue = Power antenna/amplifier turn on. Don't get cute and leave this disconnected. I thought I was a genius by not having the hideous antenna go up any more but I also had no sound.
I used all 4 RCAs. I hooked them up to the 4 RCA speaker pre-amp outputs on the Pioneer. I have full control left-to-right, back-to-front, bass, treble; everything works. Leave the purple, green, white and grey wires on the Pioneer unit alone. Tape them off individually and do not use them.
Black = ground
Red = Switched
Yellow = Constant
Orange = Illumination (your screen will dim when you turn the lights on like the OEM radio
Blue = Power antenna/amplifier turn on. Don't get cute and leave this disconnected. I thought I was a genius by not having the hideous antenna go up any more but I also had no sound.
I used all 4 RCAs. I hooked them up to the 4 RCA speaker pre-amp outputs on the Pioneer. I have full control left-to-right, back-to-front, bass, treble; everything works. Leave the purple, green, white and grey wires on the Pioneer unit alone. Tape them off individually and do not use them.