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Car Audio Wiring?

Discussion in 'E30 (1984-1993)' started by neep3r, Mar 19, 2011.

    neep3r guest

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    I'm looking for wiring diagrams/color code info for my 1986 325es. I just pulled out head unit and after a few minutes I realized I have an amp... I found a color code list on a 1991 325ic, does anyone know if this is the same as an 86 325es?

    http://www.verrill.com/car/e30_stereowiringdiagram.shtml
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    MGarrison

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    Later E30 radios are different from the earlier ones, including yours.

    If you want to heed Mooshead's advice (see: http://bmwcca.org/forum/showthread.php?t=3961&p=16771) and have your system wired up properly for optimal sound, it pretty much means rewiring the whole stereo system with your new head unit from scratch.

    If you have the 'premium' sound system, you should have the front upper tweeters by the side mirrors on the doors. BMW did their wiring in a bit of a funky way, hardly standard. Yes, it can be tapped into, but you run the risk of problems (as Mooshead's post points out) and less than ideal sound quality out of your new unit, as using the factory wiring from the center console means running through the booster amp, and at least up to the booster amp, the chassis is the ground for the speaker leads.

    I'm not going to remember the wire coloring, but, you have two wires that are the L + R channels; those run through the manual fader (notice, no ground wire for speaker neg.) and the fader splits the left and right inputs into pos. leads for the four speakers (lf, rf, lr, rr) going to the booster amp. Then there's the power, I think a ground, the light dimmer lead, and I think the wiring harness splices one wire out of the radio, one to power-on the booster amp, and the other to trigger the power antenna to raise. I think the wires coming out of the booster amp to the speakers have pos. & neg. leads to the speakers, but I think those wires are also undersized compared to what would be a more ideal wire gauge... (booster amp is tucked up above the lr fender, at least it was on my '87 'is). However, I don't think I recall locating a pinout for the booster amp connector, you'd have to test to to see which wires are the speaker leads; since it's one connector, the inputs from the stock head unit are integrated into the connecting plug.

    The good news is, E30 interiors are relatively straightforward to pull apart if you want to be ambitious and do it right. You might find a Bentley manual useful for this project, (plus countless others), although it doesn't get into ultra-detailed wiring diagrams. Rear seat comes out by pulling up with a firm tug (two spring clips on the seat bottom-front edge snap into the sheet metal rear bench area), you probably don't need to remove the seat back for running wiring, but that's easily done (two bolts, and push it upwards). Front seats unbolt (4 bolts per seat), then you have to pull the handbrake and center consoles. Unfortunately, if you want to get new wiring up to the door tweeter, it has to run through the door wiring, making that part much more involved (pulling the door panels - and, if you go that far, you'll probably need at least some of the snap clips, which, being old plastic by now, are likely to break upon removal or installation). I kinda doubt there's a crossover for the fronts with the separate tweeters, but doublecheck that.

    Anyway, if you get the handbrake and center consoles and seats out, you're down to the carpeting and it's not too bad to snake some wiring under the carpeting. Perhaps Moosehead will have some comments on how he's wired the kickpanel speakers that have the door tweeters. If you take things that far, be careful pulling the shifter console, it's a kind of vinyl-covered foam and it's easy to break the sections that extend towards the front firewall under the dash if care isn't exercised.

    Here's the etm for your year: http://wedophones.com/Manuals/BMW/1986 BMW 325 Electrical Troubleshooting Manual.pdf - see page 6500-0 and the related following pages.

    This might also be of interest - click contents, and click to the 'Radio & Special Equipment' section - http://www.bmwtechinfo.com/repair/main/561en/index.htm

    neep3r guest

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    Wow MGarrison, thank you very much for this info! I am keeping my stock OEM cassette player and using an AudioControl LC7 line output converter to convert to RCA so I can power the new speakers with my 4 channel amp. Since I am using the stock head unit I need to figure out how to wire the left & right / front & back to the line output converter... Like you said & what I found with my head unit, I have 1 yellow wire for LEFT and 1 blue wire for RIGHT - each wire has a circular connector w/ two prongs that plug into the back of the head unit. The yellow & blue wires go into the manual fader and then 2 wires come out for LEFT (yellow/black & yellow/red) and 2 wires come out for RIGHT (blue/black & blue/red). Now that I plan to wire the entire system from scratch, do I just bypass the manual fader and use the yellow (LEFT) & blue (RIGHT) for the input on the line output converter or do I use the yellow/black,yellow/red (LEFT) & blue/black, blue/red (RIGHT) after the manual fader for the input on the line output converter?

    Thank you thank you thank you, this is a huge help!!!!
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    MGarrison

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    We better clarify what you're trying to do. It sounds like you want to use the oem radio/cassette with a new amplifier and/or possibly new speakers?

    If you're planning to tap into the factory radio wiring harness running from the oem head-unit to the rear of the car (I'm assuming your car has the battery in the trunk), that's not re-wiring, that's tapping into what's there.

    I'm not sure if you're using the line converter to easily get RCA outputs to your amp, or if you're using that to get the type of signal level appropriate for your amp. The factory radio doesn't put out a line-level signal, it was a higher-power signal, which is why the factory amp is just a booster amp, the factory amp is designed to take that high level signal and bump it up (you'll see the factory amp is pretty small). In any case, you need your LC7 line converter to get a line-level signal that will work with an aftermarket amp, and obviously, the rca outputs make life easier with standard available-anywhere cabling.

    Now, if you're planning on hooking up the LC7 close to the head unit, obviously it's going to take a cable run to hookup to the aftermarket amp (new wiring is re-wiring, in this sense!). The factory head unit doesn't have a fader built in, so, if you want to be able to fade, you'll have to use the wires after the fader. That doesn't help get you a clean neg. lead for your rca cables to your amp; the problem with the chassis being the audio-signal ground is you have great potential for noise interference - and ground humm or buzzing, etc. is nothing anybody wants in a stereo install. I suppose you could _try_ it and see if it works and sounds ok, but you'd want to do that at a point where it would be easy to change course. Problem is, there's no way to get a neg. channel lead out of the factory radio, it's only those two pos. output wires - if the link you found is correct, it looks like a single BN/OG (presumably, brown/orange) wire is the neg. lead to the factory amp (although that link mislabels the LR & RR neg. leads as pos., a typo error), and if that's from a chassis ground, it's either tied into something that's wired to the chassis for ground, or just split off the radio's ground wire (presumably brown, BN). Anyway, you see the problem - you have to wire all the neg. lead channel inputs to the LC7 from one wire.

    If you were thinking of wiring-in the LC7 near your amp in the trunk, then the issue of getting its inputs from the head unit means you have to tap off the wires going into the booster amp and making sure what's what is correct - the link you found hopefully is, but should be able to be easily checked, you can use a multimeter to check for continuity. Unless you wanted to run new wiring off the appropriate leads from the head unit, which would seem superfluous, I don't think you'd necessarily gain anything from going to that much effort, particularly with the stock head unit.

    Wiring up a new amp isn't too big a deal (besides the contortionism required to mount it in the trunk), particularly if the battery's in the trunk, just follow the directions, make things are fused appropriately, correct size wire gauge, etc. However, you have to get wiring to the speakers. Pretty straightforward to the rear deck speakers if you're going to do your own cable run. Possible of course to tap into the factory wiring, but again you have to figure out what's what, as mentioned before, hopefully the link you found is accurate for your car.

    If you run your own speaker wires to the front kick-panel speakers, you'll have to decide if it's even remotely worth the hassle to do anything besides tap into the speaker leads. As I said before, obviously a hassle to get a new wire up to the door tweeter. Considering it's just a tweeter, even if you opted to rewire it, I doubt you'd get enough of an improvement in audible sound quality to say it was worth the effort.

    A thought - if you're going to the effort of wiring in a new amp and at least partial speaker wiring, why not consider a different head unit? At this point, unless your factory head unit's been substantially reconditioned, I'd say it's likely to die on you at some point (mine certainly did, although they worked a long time), which would put you back to fixing it (expensive, if it can be done at all), praying the replacement you just bought on Ebay for $5.00 actually works (it won't :p), or considering something else.

    If it were me, at the moment, I'd be looking at head units with an SD-card slot. The capacity of flash-memory cards has eclipsed all other storage media. CD: 670 mb, DVD: 4-8GB, memory sticks are up to 16gb or more, but all of those are unwieldy, and a memory stick has to stick out and could be knocked around accidentally. SD cards are up to 32gb, 64gb, and this year a 128gb card is out (pricey though, maybe $200-$250, but that will come down in time as they continue to up capacity), and plug in, easily integrated and outta the way.

    A 32gb card will hold almost 48 cd's, that's 3343 hours of music, in UNCOMPRESSED format, a 128gb card will hold about 191 cd's, 13,373 hours of music uncompressed, and if you went with mp3's, cards in those capacities could easily store thousands and thousands of songs. Unless you absolutely have to have the factory look or a weatherband channel, I'm kinda fallin' into the sd-card camp. I don't know if you'd find a cassette player with a sd-card slot, but maybe. Just a thought, anyway. I guess if they ever get to a terabyte flash memory card thats reasonably priced, I could have my entire cd accumulation at hand to listen to! Compared to shuffling cassettes and cd's though, I think I could manage 8 SD-cards! :D (if I only wanted to pay that much, that is!)
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    Brian A

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    There is a simple cross-over attached to the speakers in the kick-panels; the tweeter wires come off of that and then into the doors. Lots of tweeters have built-in cross-overs, so if you chose correctly you shouldn't have to do anything fancy.

    MGarrison explains this in his first post; only L & R come out of the head unit and the fader splits these into F/R R/L.

    See August 2007 issue of Roundel for an alternative to this all. (Author is a genius.)

    +1
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    tiFreak

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    I'm guessing you want to keep the stock head unit so you'll keep a factory appearance? I'd recommend a Nakamichi CD-400, it's pretty simple looking and you can change the illumination to amber
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    MGarrison

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    In my enthusiasm over the storage capacities, I forgot the mention the other benefit to a new head unit powering an amp is more straightforward wiring, (though you have to run some more cabling), if you're interested in having it wired up without the chassis-ground funkiness and noise potential. You can tap to the dimmer and power-antenna on leads (doublecheck if the antenna is also powered through the oem wiring, I can't recall), scrap the oem booster amp, and in running a head unit just running line-level inputs to a separate amp, perhaps be able to tap into the oem radio +12v & ground leads without having to be too concerned about over-powering the circuit - although, there still is potential for noise interference since other things are on the same circuit, as Moosehead mentions.. Otherwise, you have to find a switched +12v source for a new head unit. I suppose if you chose a new higher-end audio head unit with high-volt line-level outputs, you might need a more dedicated power supply wire than the oem wiring, for both power-handling and minimizing noise-interference potential. But, with the a head unit running an amp and powered/wired up appropriately, you'd just have to run your speaker outputs and amp-on wire to the new amp.

    Brian, thanks for the insight on the tweeter crossovers. For a so-called 'premium' sound system, BMW certainly made some unconventional choices, although I have to guess it was an economic one; they undoubtedly saved some time & money by opting to have 1 neg. lead for the 4 stereo channels, at least up to the booster amp, instead of 4. I find the stock speakers to be acceptable (barely, certainly kinda thin sounding with the oem booster amp), but hardly what most anyone would define as premium, and was at least armchair-skeptical as to the useage of a crossover for the fronts, given BMW's other choices with the factory system.

    neep3r guest

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    This is getting scary! Sorry I wasn't more clear about what I want to do and thank you guys for all the great info & advice.

    I want to keep the stock head unit and wire everything from scratch, new wiring from front to back, left to right, up, up, down, down, left, right, left, right, B, A. ;)

    So stock head unit, all brand new wiring, AudioControl LC7 line output converter (to convert signal to RCA to feed into amp), PPI Sedona 580.4 watt amp, 2 sets of MB Quart component speakers.
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    MGarrison

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    In addition to us, you should be able to find other folks that have gone down the same path at e30tech.net, r3vlimited.com, bimmerforums.com, and mye28.com (which, though focuses on 5 series, I'd presume 5er radios of the same vintage would be very similar to the setup in similar-vintage E30's, if not essentially the same). Not saying we can't help more, that's just some additional sources.

    Good luck and let us know if we can be of further help, sounds like it should be a nice install!

    neep3r guest

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    Check this wiring diagram out I found!

    [IMG]
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    MGarrison

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    oooo, nice find - now we're cookin' with gas! :p I coulda used that a few years ago myself!

    neep3r guest

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    Haha - The sad part is I am even more lost... I guess the part I still need direction on (even though a few people have already talked about this) is how to correctly wire the line output converter from the head unit.

    From the head unit there are the LEFT (YEL) and RIGHT (BLU) channel cables that go into the manual fader, LEFT turns into YEL/RED & YEL/BLK, RIGHT turns into BLU/RED & BLU/BLK. From what you guys have said and what I can see on the wiring diagram I found, there is only one ground/negative wire.

    So if I want to wire the line output converter from my head unit (which I do!), I will need to run the LEFT and RIGHT pair from the manual fader (YEL/RED & YEL/BLK, BLU/RED & BLU/BLK) - but for the negative am I daisy chaining all negatives off 1 cable???

    BTW this is for an 86 325es, the battery is in the trunk and that's where the amp, crossovers (x4) and line output converter are being mounted. I am wiring the entire car from scratch and really appreciate all your help guys, thank you.
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    MGarrison

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    Yes; obviously you'll want the correct channels connected to the corresponding leads on the LC7 so fade & balance don't get reversed, and you'll have to connect the LC7's 4 neg. speaker leads to the one.

    The way I read the wiring diagram, the brown/black (BR/BK) coming from the fader is the ground to tie the LC7 neg. leads to, and that is pin #18 for the connector going into the booster amp. Left channel leads coming from the fader to the booster amp: Yellow/Black & Yellow/Red, and if your link from 'Ted's House' is correct, YL/RD = LF (pin 15), and YL/BK = LR (pin 14). Right channel leads from fader to amp: Blue/Black & Blue Red, with BU/RD = RF (pin 20), and BU/BK = RR (pin 19).

    The only problem with mounting the LC7 in the trunk is, you may find access to the amp connector & radio wiring harness constrained, since it's tucked up above the left rear wheel arch. If you have enough slack to get the connector visible & where you can work on it, ok - otherwise it might be a bit of a challenge to be identifying the right wires, get them cut, soldered, re-wrapped &/or heat-shrink-tubing'd. I think the harness is wrapped in tape and you'll have to unwrap the tape at the connector into the booster amp so you can see the wires.

    It's interesting that the 'Ted's House' pinout has the ground wire from the fader listed as BN/OG (presumably brown/orange) but the wiring diagram in the ETM and the one you just found have BR/BK as the ground wire coming out of the fader. Ted's is for a later year tho, perhaps there was a minor change like that - but, it's important to look at the wire insulation closely, sometimes it's easy to mistake a color. Not sure if the connecting plug will have the pins numbered, but I suspect the input connector on the booster amp will.

    I guess this all sounds a bit confusing, but once you get to look at the booster amp, the connector plug, and have a chance to see the wiring, you'll see it's just going to be a matter of identifying the correct wires.

    Not that it matters, but you're retaining the original head unit because....

    a. it matches the interior?
    b. you want to keep things as original as possible?
    c. living in the Aleutian islands, you find the weather band invaluable?
    d. cassette tapes are God's gift to hi-fidelity audio?
    e. who can resist a 5-sided pentagon-shaped radio-removal tool?
    f. all of the above? :p

    In any case, sounds like the LC7 is the right thing to make it work w/ an aftermarket amp.
    Glad to be of some help! :)

    BTW, I am assuming here that your intention is to tie the LC7 into the oem radio channel outputs at the point where they (the outputs) get into the trunk area, which is at the booster amp connection point. But, yes, you could run wires from the fader output wires to the trunk area if you want to go to that extra effort; routing options include running over to & behind the kickpanels then along the door sills (which is pretty much how the factory radio wiring harness is routed), or removing the handbrake/shifter consoles and under the carpet along the transmission hump. Signal-wise, since you're converting the oem head-unit signal down to line-level, I don't think you'd gain anything by running new wires there; Since the easiest wiring shot from the center dash area to the rear is along the transmission/driveshaft tunnel, I would also wonder about the chance for spinning-driveshaft induced electrical-interference, but I don't know how likely a possibility that is (my guess is, not much, but that's only a guess).

    You should let us know how it sounds when you get it together! Oh, ya, and don't forget to unhook the battery before you start working, and if you're going to be crawling around in the trunk, put some tape over the battery leads so you don't accidentally burn off your foot in a flukey shoe-grommet-to-ankle-bracelet accidental-battery-post-shorting incident. :eek: :p

    neep3r guest

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    Thanks man. I just got done pulling a pair of 14 guage cables to the head unit and to all speakers. I don't plan on using the booster amp at all, unless I have to (do I?). I removed the booster amp and the wiring harness is very easy to work with but since I have all new wiring now I really don't know why I would need the booster amp at all. Again the plan is to go from the stock head unit to the LC7, to the 4-channel amp, to the 4 crossovers (for each woofer/tweeter), then to the speakers themselves.

    The reason why I want to keep the stock head unit is for many reasons but mainly for the stock look, lights matching the rest of the dash at night. The LC7 has AUX in so I can have a hdd or ipod and since I'm not using the head unit for power all I need it for is fm signal. :)
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    bcweir

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    Can someone elaborate on the purpose of the Nakamichi CD-400?

    I did some investigating on it, and not only is it a DISCONTINUED model, but it doesn't even offer any modern features found on every aftermarket radio out there?

    No MP3 or WMA support, no Bluetooth, no HD or satellite radio support, no CD changer support. Not even basic features like CD text!

    What advantage would this radio offer over a BMW CD43 radio?

    I've looked at aftermarket radios, and while nearly all of them offer all of the above features, one price I'd have to pay is cosmetic: the bright silver or chrome trim plate would clash terribly in my E32's interior, as well as the poly-color LCD would with my stock all-amber backlighting.

    neep3r guest

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    I think it would be great if a company could "update" oem head units with modern features. There is a market for it. More so on more vintage cars but wouldn't it be great if a company created a single din unit and replicated oem faceplates, interchangeable to fit a specific car.

    The CD43 and the CD400 are the closest head units aesthetically and are MUCH easier to wire that the stock e30 head unit (at least the one I have...).
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    MGarrison

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    Nope, and you wouldn't want to, really. I suppose you could connect the LC7 to the speaker leads out of the booster amp, but I don't know why anyone would do that.

    I wasn't suggesting using the booster amp, no need; since you said you're putting the LC7 in the trunk, I was figuring the easiest way to get it connected to the head unit would be to connect to the right wires in the original radio wiring harness which is already routed from the head unit through the car into the trunk - saving the effort of running wires from the head unit area into the trunk. You've already seen the booster amp uses one connecting plug, so the inputs from the head unit and wires out to the speakers are all in that single plug, which just means a little more effort required to ID the needed wires.

    Sounds like you've run new wires from the fader outs, tying into the fader at the dash, and run those wires back to the trunk - works just as well, if not better; just a little more effort. Since the LC7 has an aux input, consider running an extension input cable from the LC7 up to the dash, center console, or glovebox (I'm guessing you'd need at least a 6 ft. cable) - then if you want to plug in an ipod or whatever, it can be easily accessible to you sitting up front. Obviously easier to do that while you're doing the other cable runs and have everything apart.

    Does the LC7 automatically switch to the AUX input if it detects a signal? If it switches to the AUX input due to a plug being plugged in, leaving an extension cable plugged in all the time would supercede the radio. If that's the case, it still might be worthwhile to run the cable, but mount the LC7 in the trunk so it's accessible to plug and unplug the extension when needed. Not as convenient as being able to just plug into an at-hand extension cable, but since the oem radio has no AUX input, that's all you could easily do.
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    Brian A

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    Oooooooooohhhh maaaaaaaaaannnnnnnn! This diagram is awesome.

    Wherever you got it, was there one also for the 1991 E30 head unit????????

    I am trying to figure out the wiring to the round plug, per the following:
    http://bmwcca.org/forum/showthread.php?t=4158
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    tiFreak

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    where did you read that it's discontinued? I can still find new ones for sale

    I guess the advantage of it over a CD43 is that it's easier to find
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    bcweir

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    Tifreak, Why do you think "discontinued" means they can no longer be found?

    By that definition, it would suggest that when a manufacturer no longer produces a unit, every other existing unit of that model magically "disappears" from the marketplace.

    Did every E36 magically disappear off the face of the earth when it was replaced by the E46?

    Discontinued means just that. It means it's no longer being produced as a new unit by the manufacturer, presumably superceded by a newer model offering exactly the features that were missing in the prior model. My information indicates that the Nakamichi model we speak of went out of production in 2007, a surprisingly late and recent date for such an antiquated radio. By 2007, radios offering MP3/WMA playback, CD text, satellite and HD radio as well as USB, Ipod/Iphone support were widely supported by the aftermarket. Quite likely, Nakamichi stopped making this unit to make room in its production for an updated model.

    The CD43 is also a "discontinued" model. However they can still be acquired used on the open market, and in some rare instances, even as NOS (New Old Stock, which means it's technically a new unit that's never been sold, opened, or installed into a vehicle before).

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