# 2001 BMW 740 Wiring Help



## bigaudiofanatic (Mar 1, 2009)

I need help with the wiring of a BMW 740 series, first off do I need a JL clean sweep and mtx re-q for my new amps? OR is there wires to tap into that will be preouts? Any help would greatly appreciated.


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## bigaudiofanatic (Mar 1, 2009)

Anyone?


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## DynaudioNut (Jan 1, 2010)

I have a 1995 740IL which is set up a little different than yours due to the upgraded electronics in the newer models, but to make a long story short. If you don't plan on by passing the wiring set up in that car, take it to a reputable place and have it done correctly. Too many things that are interdependent on these babies...Good luck.


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## bigaudiofanatic (Mar 1, 2009)

I have done plenty of audio installs all I need is a diagram or some guidance for which wires to use. Doing the install is not the problem.


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## Mless5 (Aug 21, 2006)

Have you looked on e38.org?


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## bigaudiofanatic (Mar 1, 2009)

I have the closest thing I could find was this. Basslink install wire instructions
But I do not know if there is another option.


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## danno14 (Sep 1, 2009)

As I understand there are no wires that are the equivalent of preouts. More info here:

Mojo's Quick-N-Dirty™ E38 Subwoofer Installation Guide - Bimmerforums - The Ultimate BMW Forum

Good luck!


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## SomeGuy748 (Feb 24, 2010)

Your car is fiber optic and has a multi channel amp in it from BMW. The stock amp has speaker specific channels for each set of speakers in the car. If you are trying to add amps to power all the speakers in the car, yes, you will need something between the stock amp and your new amp so you can get full signal into the new amp. If you are simply adding a sub amp, you can grab the factory sub outputs off the BMW amp and use an LOC to convert to an RCA. This is a fairly complicated car to do a system in. I've worked on three of them in the last two months and each one was a pain.


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## bigaudiofanatic (Mar 1, 2009)

Thank you for the information. Today I am working on installing the JL clean sweep. I came accost a problem. There are 3 brown wires one in which is probably power. but I am not sure which brown wire goes to which of the channels if you could help me with this it would be much appreciated.


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## SomeGuy748 (Feb 24, 2010)

There should be a brown wire twisted up with each colored wire if you are using the output wires or a colored wire with a brown stripe. Be carefull, the smaller wires coming out of that amp may not play full range. The BMW amp has specific channels for all the speakers and they are filtered outputs. The browns should never be power in that car.


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## bigaudiofanatic (Mar 1, 2009)

The big thick brown wire is ground. So should I just wire them and see if it is full range or not? What would be the next step if they are not full range? Also if I do not need the mtx re-q for bass and just use a LOC than how will the bass adjust with the music. The reason I say this is the JL "from what I understand" you have to use there volume knob once installed.


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## DynaudioNut (Jan 1, 2010)

Best advice. Trust me on this one, by pass all that junk and run your own wires. go active and enjoy your music. Too many things can go wrong when messing with factory wiring.


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## bigaudiofanatic (Mar 1, 2009)

Oh I was doing that already. Using the stock wiring for powering speakers with 110 watts would be stupid. The owner wants the stock hed unit so that will have to stay.


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