Sal Cie 0 Report post Posted July 3, 2017 I am attempting to replace my Kenwood KDC2025 with a newer Kenwood my old radio has a blue wire attached to a lone port on the back of the unit. Any idea what it's for? Can't find it in any manual diagrams. Share this post Link to post Share on other sites
hubfreightbob 0 Report post Posted July 10, 2017 Usually a blue wire is a remote amp turn on . When you turn on the head unit the blue wire sends a signal to turn on the amps . Share this post Link to post Share on other sites
Kidnmeiieh 0 Report post Posted July 10, 2017 The blue wire is usually a remote wire that is used to power on a amplifier or other. When you turn on your Kenwood, the blue wire becomes live and if it were connected to an external amplifier, it would signal the amplifier to turn on. Hope this helps Share this post Link to post Share on other sites
