I need information on what wires use fuses on a sony cdx-4000

Hi there,

You may find your Sony unit has the fuse built-in to the back of the player - hence, modern units no longer require an in-line fuse in the wiring.
yellow = 12v constant or battery power
red = 12v switched or ignition power
black = 12v ground or chassis ground
blue = power antenna turn on
blue/white = amplifier turn on
white = left front speaker +
white/black left front speaker -
gery = right front speaker +
grey/black= right front speaker -
green= left rear speaker +
green/black left rear speaker -
purple = right rear speaker +
purple/black= right rear speaker -
lt blue= cell phone mute input
Hope this helps...