[ins1dez]

Hello

I would like to know if the battery distribution box has a permanent 12v or only when i turn on the car?

I want to know this because i want to get power for amplifier from it, and i want the amplifier to start ONLY when i have ignition on.

[cpie168]

Bump for this. I would like to know the answer as well.

Do the spare ports on the rear power distribution box turn on with the ignition, or are they always hot? I'm looking to create an extra cigarette lighter socket in the trunk and would like to tap into a wire that's NOT always hot, since I'll be using a powered cooler with it and don't want it to drain the battery while the car is off.

Thank you very much in advance.

[ctuna]

System dependent. (there are three systems )
1)Hi Fi 12 Volt line is switched.
2)I think the L7 is as well .
3)Stereo no amp no line. (base system world wide)
Unless your car is pre wired.
http://www.e90post.com/forums/showth...ight=head+unit

http://www.e90post.com/forums/showthread.php?t=138949

The amp powers up as soon as the car awakes
and is on as long as the car is awake.
See the above link for details.

Technic uses the Harness 12 volt line as a amp turn on signal I believe.
Best to get and amp with signal sense for turn on unless you want to run a line from one of the switched 12 Volt signals.

Battery distribution just has fuses or fusible links.
Always on .
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja

[cpie168]

Thank you for the information.

I'm totally new to this; can you please tell me where the HiFi or amplifier 12V line is? My car has the basic BMW Professional audio unit, not the Logic 7 one.

A picture would be great, if possible. Thank you very much.

[ctuna]

Base system might have no harness.
And no lines to the Trunk.
There are three systems the no pay for it system in the US
is the middle one. In other country's its a no amp system.
Details in the following links.
You need to identify the sound system exactly.
Also Technic makes a harness for all three systems
that takes there differences into account.
Please study these.

BMW stereo types
http://www.e90post.com/forums/showthread.php?t=352586
http://www.e90post.com/forums/attach...2&d=1266451970
http://www.e90post.com/forums/attach...2&d=1260829447
http://www.e90post.com/forums/showthread.php?t=343673
http://www.e90post.com/forums/showthread.php?t=138949
http://www.e90post.com/forums/attach...1&d=1209780605
http://www.e90post.com/forums/showthread.php?t=641323
http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/
http://www.e90post.com/forums/attach...1&d=1209780865
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.musicarnw.com/page-2/
http://www.e90post.com/forums/attach...4&d=1278871872

[cpie168]

Thanks ctuna. That's a whole lot of information.

I just realized that my system is the most basic "stereo" system, which means it doesn't have an amplifier in the trunk. Does that mean I will not be able to take the switched 12V supply from the amplifier for my DIY cigarette lighter socket?

What other choices do I have? Is there any other switched 12V line located in the trunk?

[ctuna]

Technic makes Harnesses for all systems.
And I'm pretty sure they all take into account switching the amp
on and off.
And its better wiring than most people are likely
to fabricate.
Also before planning a system you better read the Audio build thread carefully because each system
has its own set of problems and solutions.
The eq in the base system must be compensated for when you modify.

And easy solution is a MusicarNW system it has
everything you need but, not inexpensive but
nothing is with these cars.

Read and study and then study some more
http://www.e90post.com/forums/showthread.php?t=641323

[taibanl]

Originally Posted by cpie168

Bump for this. I would like to know the answer as well.

Do the spare ports on the rear power distribution box turn on with the ignition, or are they always hot? I'm looking to create an extra cigarette lighter socket in the trunk and would like to tap into a wire that's NOT always hot, since I'll be using a powered cooler with it and don't want it to drain the battery while the car is off.

Thank you very much in advance.

It is constant.