Aftermarket head unit doesn't turn off

[blowjustinup]

Hey all, I've wired an aftermarket head unit into my B6 A4 (2005) and I can't get the thing to turn off. I take the face plate off which seemingly turns it off, but it's killing my battery (I think the amp is staying on) to the point where if I leave the car for more than 10 minutes I need to jump it. I've checked the wiring and everything looks to be hooked up correctly.

Harness: https://axxessinterfaces.com/product/AX-ADXSVI-AU2
RAP module: https://axxessinterfaces.com/product/XSVI-9004-NAV
Head unit: https://www.pioneerelectronics.com/P.../AVIC-W6400NEX

Someone tell me there's a common mistake that I'm making here.. I think I can probably just tap a fuse for switched power like in any other car (maybe?), but I'd like to keep the functionality that keeps the radio on until you pull the key out.

EDIT: I attempted to connect the switched power to multiple fuses that should be switched and still got the same behavior.

[Robbob1125]

I did the same thing on mine, head unit wouldn't turn off with key out of the ignition.
I pulled the knee cover off under the steering wheel and found a hot wire that was live only with the key in the ignition.

Spliced in the radio harness positive (red) to and worked wiht out overloading any fuses.
I used the dash wire bundle to the left of the steering column.

[BARRY]

https://enfigcarstereo.com/index.html is a site sponsor and knows the platform very well. haven't heard of this issue with any of their harnesses or adapters.

[Charles.waite]

Our radios use both switched 12V and constant 12V. So they're more or less always on, they just have logic to turn off when the ignition is switched off. You might be able to transfer the power wire to the switched wire in the radio adapter harness.

In any event, both power wires are in the factory harness so you shouldn't have to splice anything new, just combine or relocate a factory wire.

[blowjustinup]

You might be able to transfer the power wire to the switched wire in the radio adapter harness.

What do you mean by that?

Spliced in the radio harness positive (red) to and worked wiht out overloading any fuses.

Would this be any different than using a fuse tap? I tried a fuse tap on multiple fuses yesterday and just got the same exact behavior.

[Charles.waite]

Our radios have separate power wires for constant and switched wired in to the harness. I don’t know what your harness is doing but make sure the switched and constant wires are wired to the correct pins on the new headunit, and then if they are try removing the constant 12V and making switched provide power to the new headunit.

Again I don’t know if your new headunit is supposed to get power from switched or from constant (or from both, like the factory stereo) so I cant tell you exactly how to fix it. I’m simply saying the switched power wire is literally already there in the factory radio plug, so finding a random switched wire elsewhere and using a tap is a bad idea sine the wire you want is already present in the wiring harness.

[ReinS]

Our radios have separate power wires for constant and switched wired in to the harness. I don’t know what your harness is doing but make sure the switched and constant wires are wired to the correct pins on the new headunit, and then if they are try removing the constant 12V and making switched provide power to the new headunit.

Again I don’t know if your new headunit is supposed to get power from switched or from constant (or from both, like the factory stereo) so I cant tell you exactly how to fix it. I’m simply saying the switched power wire is literally already there in the factory radio plug, so finding a random switched wire elsewhere and using a tap is a bad idea sine the wire you want is already present in the wiring harness.

Charles, there actually isn't switched power wire in factory plug. Only constant power wire. Switched power is given by can-bus. Check wiring and look if there isn't bridge between yellow and red wire (red goes to yellow or vice versa). If constant yellow is connected to radio red it causes battery drain. Maybe new can interface box is faulty? You can take switched live to HU red from ignition switch S pin. I use this solution 8 years and zero issues. Also acts like factory stereo. Remove key and it goes off. Key in and turn a little bit. No need to turn ignition on and it turns on.

[Charles.waite]

There is switched 12v in the later Quadlock radios, 100% sure there is on the ISO-plug radios as well.

I know it uses CAN for sending turn on signals in some cases but it’s not sending switched power over Can. CAN wires are like 22awg. Power wires are 12-14. Huge difference. And anyway, our radios have a dedicated amp turn on wire.

[userbob0001]

I'm equally sure there isnt, but here's the pintout if you want to prove me wrong.

Radios pull power from the constant line whether they get their switched signal directly or over CAN, so the switched wires don't need to be large.

The Amp wire is an output, so it isn't terribly useful in this case.

[Robbob1125]

Would this be any different than using a fuse tap? I tried a fuse tap on multiple fuses yesterday and just got the same exact behavior.

I dont see why not But I didnt want to risk a fuse that remained on with key off or overload one. I know the cars are/can be picky when it comes to their fuse and power managements.


But this was the thread I stumbled onto when I had the problem.
https://www.audizine.com/forum/showt...doesnt-turn-on

And I used this to figure out a 'switched 12v' source.
http://www.a4mods.com/index.php?page...tml&category=4

Hope it helps ... Good luck