12V outlet power feed tied to audio power?

paloalotpeter · 10-08-2015, 06:06 PM

I want to have one of my 12V outlets powered on whenever the radio is on. I use it to power a bluetooth adaptor to stream music from my iPhone. This includes listening after I stop the engine but before I take the key out. The power for the 12V outlet in the ashtray and in the center console turns off as soon as the engine is stopped which is annoying when you want to sit and listen to something after you've turned the engine off.

My 2009 335d did not come with the passenger footwell 12V outlet. I added it per this DIY: http://www.e90post.com/forums/showth...tlet+passenger

I ran the power back to the fusebox but now that outlet is permanently powered on. I would rather it was powered only when the radio was on as I use the outlet to power an audio Bluetooth adaptor and the auto-stop feature is nice when I pull the key out. Can someone suggest a better place to get power from?

Thanks

matteblue3er · 10-09-2015, 02:58 PM

Depends on how you want the power to behave.

You can have it wired to a switched ignition source, however the radio can still play without ignition switched. In this case, power to the bluetooth adapter would be cut off.

To keep power on whenever the radio is on, you can use a relay and trigger it with pin 13 from the head unit harness. DO NOT POWER AN ACCESSORY DIRECTLY OFF PIN 13! There is the possibility to draw too much current and it may damage the head unit. I don't think this lead is fused so if it does draw too much, there's no telling what it could potentially damage.

Pin 13 turns on when the user activated circuit in the car is triggered. This circuit is triggered by unlocking/locking the car, opening or closing doors, or when the car wakes itself to do self tests.

So the adapter may be powered periodically if you use the latter method to power the adapter. If you are close to your parked car, you may run into a situation where the adapter turns on randomly and pairs with your phone.

paloalotpeter · 10-10-2015, 01:17 PM

Thanks - the pin 13 suggestion is exactly what I was looking for. Sorry for the remedial question but how do I get access to the head unit harness? I've searched the threads but have not been able to find that info.

VTECaddict · 10-12-2015, 04:15 AM

You have to pull the head unit out...

paloalotpeter · 10-12-2015, 11:08 AM

Thanks. Is there a guide or DIY on how to do that? I've searched the threads extensively but haven't found it.

10-08-2015, 06:06 PM	#1
paloalotpeter New Member 5 Rep 15 Posts Drives: 2009 335d Join Date: May 2010 Location: Palo Alto, CA iTrader: (0)	12V outlet power feed tied to audio power? I want to have one of my 12V outlets powered on whenever the radio is on. I use it to power a bluetooth adaptor to stream music from my iPhone. This includes listening after I stop the engine but before I take the key out. The power for the 12V outlet in the ashtray and in the center console turns off as soon as the engine is stopped which is annoying when you want to sit and listen to something after you've turned the engine off. My 2009 335d did not come with the passenger footwell 12V outlet. I added it per this DIY: http://www.e90post.com/forums/showth...tlet+passenger I ran the power back to the fusebox but now that outlet is permanently powered on. I would rather it was powered only when the radio was on as I use the outlet to power an audio Bluetooth adaptor and the auto-stop feature is nice when I pull the key out. Can someone suggest a better place to get power from? Thanks
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10-09-2015, 02:58 PM	#2
matteblue3er Captain 238 Rep 947 Posts Drives: Racecar Join Date: Jul 2015 Location: Philly iTrader: (0)	Depends on how you want the power to behave. You can have it wired to a switched ignition source, however the radio can still play without ignition switched. In this case, power to the bluetooth adapter would be cut off. To keep power on whenever the radio is on, you can use a relay and trigger it with pin 13 from the head unit harness. DO NOT POWER AN ACCESSORY DIRECTLY OFF PIN 13! There is the possibility to draw too much current and it may damage the head unit. I don't think this lead is fused so if it does draw too much, there's no telling what it could potentially damage. Pin 13 turns on when the user activated circuit in the car is triggered. This circuit is triggered by unlocking/locking the car, opening or closing doors, or when the car wakes itself to do self tests. So the adapter may be powered periodically if you use the latter method to power the adapter. If you are close to your parked car, you may run into a situation where the adapter turns on randomly and pairs with your phone.
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10-10-2015, 01:17 PM	#3
paloalotpeter New Member 5 Rep 15 Posts Drives: 2009 335d Join Date: May 2010 Location: Palo Alto, CA iTrader: (0)	Thanks - the pin 13 suggestion is exactly what I was looking for. Sorry for the remedial question but how do I get access to the head unit harness? I've searched the threads but have not been able to find that info.
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10-12-2015, 04:15 AM	#4
VTECaddict Where'd my VTEC go? 479 Rep 6,067 Posts Drives: 06 330i 6MT Join Date: Mar 2009 Location: Seattle, WA iTrader: (4)	You have to pull the head unit out... __________________ AW/Terra \| ZSP \| ZPP \| ZCW \| iDrive \| CA Mods: BC BR coilovers \| Blacklines \| M-tech rear \| dual exhaust \| M3 steering wheel \| BMW SSK \| ZHP shift knob \| High-kick CF spoiler \| NBT Retrofit M3 front control arms \| M3 rear guide rods \| Manzo rear toe and camber links \| Monroe rear shock mounts \| Varrstoen ES1 19x9.5+20 Front, 19x11+25 rear
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10-12-2015, 11:08 AM	#5
paloalotpeter New Member 5 Rep 15 Posts Drives: 2009 335d Join Date: May 2010 Location: Palo Alto, CA iTrader: (0)	Thanks. Is there a guide or DIY on how to do that? I've searched the threads extensively but haven't found it.
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