Switched 12v from composition media?

[Dink]

anyone know if there is a switched 12v that can be sourced from the composition media stereo

i am going to install a ktp-445 to the oem stereo but need to find a way of it being switched on with the stereo.

i would of used the ignition switched supply in the fuse box but the stereo can be switched on without the ignition so kind of defeats the object

i also thought about using a low voltage switch off relay but don't fancy putting the extra cycle load on the battery.

anyone got any ideas?? even an output from the bcm could work i guess

[joe6]

Not familiar with the Polo media set up or wiring diagrams yet as 11 weeks to delivery! Just a thought but I would think there is a supply from the radio to the CD player that could be accessible for switching a relay? but would need to careful about pulling any power from it as it presumably goes through the radio so could blow the lot? BCM is a possibility but much of that is ignition switch controlled.

[Dink]

i just need a voltage supply as no current will be drawn as it is just the turn-on for the amp

the stereo in the polo is all in the glove box cd player and the screen is just that.

if the stereo was only usable with the ignition on it would be easy.

i'm just wondering whether or not there is a signal for the steering wheel buttons or something from the stereo that i could pick up a 12v from

[Grizwald]

drop a wire down to the back of the 12v aux/cigarette lighter socket.

[Dink]

drop a wire down to the back of the 12v aux/cigarette lighter socket.

i've not looked into it but i guess that only comes on with the ignition which isn't going to work

[Grizwald]

Right, sorry misread what you were trying to do, you're into Canbus magic there.