# Center console wiring... need help with switched power



## mquetel (Jan 30, 2003)

I spent a good chunk of today attempting to complete an XM install. The idea is to hard wire an XM Roady at the center console tray by running the OEM aux input down then tapping into the switched 12v that is (supposed) to be there in the phone harness using this adapter. Well, I got the aux input done, no problem. I then mounted the XM antenna on the rear deck and ran the wiring under the child seat hook into the trunk. Followed the existing wiring harness into the car, then ran the antenna feed under the rear seat and carpet into the center console. Finally I tapped into the existing phone harness as suggested by these two nice write-ups: first and second.

Now starts my problem. I tapped into the violet and white wire assuming that is switched power (numerous online sources indicate it is). I find two brown wires (again, numerous sources indicate brown is ground). The first is a larger guage wire that is in the phone bundle, but instead of terminating at the connector, it loops back under the carpet where the wires originate. The second is the same guage as the power and terminates at the connector. I decided to tap into the larger guage wire assuming that is the ground (later I read in the 2nd writeup that the larger guage wire is not ground, but something else  ). I plug everything in, turn the key and no power to the XM reciever. I took the connections apart, re-read everything, then connected back to the violet/white for power and changed to the smaller brown for ground. Again, nothing happens.

At this point, I temporarily abort the project and go buy a volt meter. :eeps:

Later, checking those two wires (with the key in and the car powered up) it indicates that I'm getting no power at the location.

So... thanks for sticking with this so long... I have questions:

- Should I expect that harness to be powered?
- Did I perhaps screw the pooch tapping into the larger guage brown wire assuming it was ground?
- If I need to check a fuse, how and where would I do that?
- Anyone have any suggestions? I'm stumped at this point.

Oh, and yes, the reciever works when I plug it into the cigarette lighter.

Thanks in advance for any helpful insights and suggestions.


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## The HACK (Dec 19, 2001)

http://www.bimmerfest.com/forums/showthread.php?t=8543&highlight=glove+box

See the above thread for reference on how to get to the glovebox.

Get a Bentley's manual if you can, it'll have a chart showing you which fuse control what accessories. Once you can get that figured out, you can figure out which wire does what and what you need to tap into.

Still, it never hurts to have a multimeter when you work on your car's electrics.


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## Kaz (Dec 21, 2001)

The purple/white (pin8) and brown (pin17) wires are switched +12 and GND respectively. I've used these on 2 phone installs in my own car. Now, if the phone harness wiring has completely changed for 04, it's possible they're different, or are active/inactive depending on whether a ELO plug is installed in back or something. :dunno:

I guess tapping the lighter isn't an option since, IIRC, that is always live.

The glovebox is a good idea, and there are 2 ways of going at it. The easiest way is to find an open circuit and use a faston for juice, or you could use one of the true distribution blocks, though the latter is a MAJOR PITA and I wouldn't bother unless you're a real neat freak. There are plenty of places under the console for chassis ground.


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## mquetel (Jan 30, 2003)

The HACK said:


> http://www.bimmerfest.com/forums/showthread.php?t=8543&highlight=glove+box
> 
> See the above thread for reference on how to get to the glovebox.
> 
> ...


Thanks for the link, could come in very helpful. Couple of questions/comments, though...

- I thought the Bentley manual had not really been updated in quite some time and BMW is fiddling around changing the wiring harnesses fairly often. I'm worried it may have as much misinfo as info.

- Is it not appropriate to tap into the wiring already in the center console, or is the fuse box the place to do it?


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## The HACK (Dec 19, 2001)

mquetel said:


> Thanks for the link, could come in very helpful. Couple of questions/comments, though...
> 
> - I thought the Bentley manual had not really been updated in quite some time and BMW is fiddling around changing the wiring harnesses fairly often. I'm worried it may have as much misinfo as info.
> 
> - Is it not appropriate to tap into the wiring already in the center console, or is the fuse box the place to do it?


Where ever it's most convenient for you. I would prefer doing it directly from the fuse box since it's easy to hook up a multimeter to the exposed terminals to test and see which wire supplies what power.

And for ground, just hook up the cable to ANY exposed screw or not that's connected to an unpainted surface and you'll be fine.


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## Kaz (Dec 21, 2001)

mquetel said:


> - Is it not appropriate to tap into the wiring already in the center console, or is the fuse box the place to do it?


I agree, the Bentley is near useless for something like this. I used it to figure out the pinouts for the LCM for my rear fog project, but as we all know from bluer1's work, facelift cars are 100% different.

As for tapping wires, consider the original intended load on the circuit and whether it's fused or not as part of determining whether or not to use something. The one in the phone harness probably isn't meant for more than an amp or so, since for phone use, there is an always-on (pin10) line that's most likely used for the higher-current functions such as charging the handset.

Two things I always do is probe potential lines with a DMM, and never cut any factory wires or harnesses in order to be able to return everything to normal or in case you phuk something up and need to revert.


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## mquetel (Jan 30, 2003)

Kaz said:


> The purple/white (pin8) and brown (pin17) wires are switched +12 and GND respectively. I've used these on 2 phone installs in my own car. Now, if the phone harness wiring has completely changed for 04, it's possible they're different, or are active/inactive depending on whether a ELO plug is installed in back or something. :dunno:
> 
> I guess tapping the lighter isn't an option since, IIRC, that is always live.
> 
> The glovebox is a good idea, and there are 2 ways of going at it. The easiest way is to find an open circuit and use a faston for juice, or you could use one of the true distribution blocks, though the latter is a MAJOR PITA and I wouldn't bother unless you're a real neat freak. There are plenty of places under the console for chassis ground.


 I'm gonna show some ignorance here...

Not familiar with what an ELO plug is... could you expand a bit on that?

Also, sorry for the complete noob question, but how would I identify an open circuit at the fusbox to use? As I mentioned earlier I did get a multimeter today (not that I really know how to use it).

Is there a particular size of faston that I need to use?


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## mquetel (Jan 30, 2003)

Kaz said:


> and never cut any factory wires or harnesses in order to be able to return everything to normal or in case you phuk something up and need to revert.


Words I'm going to learn and live by from now on...


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## Kaz (Dec 21, 2001)

The aforementioned thread discusses the procedure in a bit more detail. Also try http://www.bimmerfest.com/forums/showthread.php?t=8516

The ELO thing (I remember now, it's called the SES Jumper) is a thing that goes onto one of the BACK harnesses for the phone to route signals around the car. Some bodies on some years use this and some don't. It's part of the huge mess that is BMW phone prewiring. In either case, you really don't need to worry about it.


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## mquetel (Jan 30, 2003)

Kaz said:


> The aforementioned thread discusses the procedure in a bit more detail. Also try http://www.bimmerfest.com/forums/showthread.php?t=8516
> 
> The ELO thing (I remember now, it's called the SES Jumper) is a thing that goes onto one of the BACK harnesses for the phone to route signals around the car. Some bodies on some years use this and some don't. It's part of the huge mess that is BMW phone prewiring. In either case, you really don't need to worry about it.


Cool, thanks for that great link also...


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## Terry Kennedy (Sep 21, 2002)

mquetel said:


> Now starts my problem. I tapped into the violet and white wire assuming that is switched power (numerous online sources indicate it is). I find two brown wires (again, numerous sources indicate brown is ground). The first is a larger guage wire that is in the phone bundle, but instead of terminating at the connector, it loops back under the carpet where the wires originate. The second is the same guage as the power and terminates at the connector. I decided to tap into the larger guage wire assuming that is the ground (later I read in the 2nd writeup that the larger guage wire is not ground, but something else  ). I plug everything in, turn the key and no power to the XM reciever. I took the connections apart, re-read everything, then connected back to the violet/white for power and changed to the smaller brown for ground. Again, nothing.


If you look at this PDF file from my illuminated cupholder DIY, you'll find the pinout of the cell phone prewire harness. I'd suggest going by the pin numbers rather than the wire colors, since BMW tends to change colors. The pin numbers should be molded on the face of the connector. You can also use thin paper clips or similar to poke into the connector face to pick up the signals for your multimeter - then when you find one you can proceed to actually tapping the wire. That way you don't mess up the other wires in the harness while poking around.


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## captaindrewle (Nov 19, 2002)

Check this out on my MY2003 330Ci (production: Dec 2002)

Pin #2: Ground
Pin #6: 12V switched










Pin #2: Ground
Pin #3: Ambient light power


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