I have my entire music collection on an obsolete Samsung Galaxy s8 wired to my cassette deck adapter. I finally figured out how to prevent the cassette sound adapter from ejecting by simultaneously pressing the AM/FM and tape eject buttons, then pressing 5 twice. Now I want to run a charge wire to this phone that is magnetic mounted on the dash. What are my best options to connect power? I have been using a USB charger through the cigarette lighter and that is messy. I would like to run a dedicated wire from a proximate power source, mostly unseen up to the phone. Where would you tap 12v?

Here is a clip of the manual that says 1998, but obviously the settings are the same for my 2004 radio. There are seven presets like AF, service reminders, telephone, RDF on or off; and of course tape eject on/off.

 

I tapped in to the 12v aux power source behind the glove box to run a 2x USB, one for my dash cam and one for a power cord run through the center console between the seats

 

Thanks for that. Do I need to remove the glove box to get at the aux power source? Maybe you have a picture of the wire?

 

See Fig 14 of Auxilliary Power Socket - C2A1403.pdf

 

Thanks so much for Fig 14 I would never have found it. It was both tucked away and secured to the frame out of view. Here is a picture so others may find it. It is a three wire, ground, 12V positive always on, 12V positive with ignition on only, so the best of both worlds. Just four torx and four phillips head screws to remove the glovebox and access the wire. There is enough slack in the second picture letting the aux power hang down so I don't need to remove the glovebox a second time to route the wires.
BTW, also an opportunity to replace the incandescent bulb with an LED glovebox light.

Three wire auxilliary power behind glovebox

Box reinstalled and wire easy to connect

 

Thank you. I always remember that this was hard to find when I tried once.

Great references.
John