Radio troubles...

[Sixdown]

Yes, I have searched plenty, but it's all confusing me to hell. Even the wiring diagram is messing with my brain. I guess I'm just freaking out for no good reason.

Well, I've installed numerous headunits in the past but never encountered wiring like that in my '89 535i. So, I've bought the headunit, I know theres an amp, but I have no idea where to start. The stock radio is out, but the wiring is confusing, meaning there are just too few wires for so many speakers. I guess this is the problem with the amp, but is there a way to keep the amp, not having to lay wiring, and just put in my Blaupunkt? I want it simple, and I do not need massively nice sound or anything. Sure, my integrated antenna will give worse reception, but so be it. I simply want a CD player.

So, where to start? I have access to a PAC OEM2 that I had in my 525e. Can that help?

[DDK's 525]

Check out this. It should help you out a ton. Let me know if it works as I am getting ready to do as you are.
http://www.bmwe34.net/e34main/Upgrade/Stereo_radio.htm

[Sixdown]

See, theres a problem. My car has the older 1989 wiring, and that page has one image of it and nothing else at the very bottom.

"There is no harness for the older radios, so you will have to tap on the factory wires. Again, don't forget to connect the power antenna wire."

And because of the above, I don't know where to start. There is no harness or anything, but just a few of wires going into the stock unit, and over 15 coming out from the new headunit. Makes no sense.

Do I just cut the connectors off the original wiring and then solder them to the new wiring from the headunit?

[Sixdown]

I already have gone through a hundred threads...I can't figure it out.

[DDK's 525]

The stock system uses a common ground for the speakers so you will only have positive speaker leads from the amp to the head unit. There should also be some brown wires by themselves and connected to the radio chasis (at least thats the way mine are). You only hook up the positives from the head unit to the positives going to the amp. As for the negatives, I have read to tie the negatives of the head unit together, and to just leave them un-stripped, not connected to anything. Then take the brown wires and connect them to the chasis of the head unit. I am pretending to know what I am talking about as I have not yet hooked up my new stereo yet, but this is the info I have gathered.

[genphreak]

Yes it is weird. Good news is the early one cars have the best stereos.

The fader in the dash is fed the signal from the head unit and then all 8 high output wires goto the amp. Best thing one can do is replace the head unit with one that has a low level output, wire these into a low level amp at the rear via the same wires and the stock amp (but remove the booster section and link the low level feeds to the new amp, then bring the speaker outputs back again for distribution to the speakers via the shell of the old amp (and the cool crossover the early versions had...)

I posted at length ago about this last year... you can find those posts witout too much trouble. I hope they help.

[Sixdown]

Has there ever been a DIY procedure written out for this? I'm gradually understanding the wiring, but do I really have to bother with the amp at all? I don't need super bass sound or anything, only the ability to play CD's

DDK525 seems to be on track, describing what I want to do.
To sum it up, will the new headunit work if I connect the stock antenna, power, and speaker wires to it, as shown here: http://www.bmwe34.net/e34main/Upgrade/Data/Stereo/Old_big.jpg
I mean, at least there are seperate wires for the speakers, contrary to what I originally assumed, but will it work is still the question.

[525i winter driver]

Has there ever been a DIY procedure written out for this? I'm gradually understanding the wiring, but do I really have to bother with the amp at all? I don't need super bass sound or anything, only the ability to play CD's

DDK525 seems to be on track, describing what I want to do.
To sum it up, will the new headunit work if I connect the stock antenna, power, and speaker wires to it, as shown here: http://www.bmwe34.net/e34main/Upgrade/Data/Stereo/Old_big.jpg
I mean, at least there are seperate wires for the speakers, contrary to what I originally assumed, but will it work is still the question.

you need the amp for the speaker crossovers... you can bypass it inside the amp or build your own crossovers but it should work fine through the amp, it just muffles the sound a little.

in addition to the connections on the diagram in the link, which should all be connected to the amp (via the existing wires behind your stock unit), you need to supply power your unit and a ground... (these wires should also be connect to your stock hu).

i actually connected my speaker grounds, there are existing spkr grounds going into my amp but i have a very early model, not sure about others.

since all 4 grounds are the same colour it took a lot of trial and error and frigging with the fader and balance controls on my h/u before i got it right, but it works perfectly now.

[Sixdown]

Thanks everyone! I've finally understood the wiring. Colors are not standard in the car, but I can use the bmwe34.net diagram to figure it all out and I'll update on results with the Blaupunkt Monterrey.

1) Do you just cut off the plugs from the original wiring that plug into the stock headunit and solder them to the new wiring from the new headunit?

2) The Blaupunkt comes with a wiring plug that has both negative and positive wires, but the stock unit only has one set, which I believe are positive.

Can I get this confirmed?

[Sixdown]

EDIT 2: Apparently the balance and fader is reversed, but it still works. I got the wiring correct according to the Blaupunkt manual and the bmwe34.net diagram, so I can't figure out why its reversed yet still works perfectly.

EDIT: SUCCESSFUL. I managed to install it properly, and discovered that the protruding bolt was in fact the grounding. The stereo is nice and crisp, and better than what it was and, oddly enough, with the stock amp too.
Again, thanks everyone! The wires for the interior light dimmer dont seem to do anything even though I soldered them together.


About to install the new radio. I've cut and soldered all the wires, including the plugs, onto the new wiring from the Blaupunkt, but my question still remains...what do I do about the negative wires jutting out from the new headunit? Obviously they must go somewhere. The stock headunit had them go to a grounding bolt that juts out the back of the unit, and the Blaupunkt also has that, but I am unsure if the new headunit uses the bolt as a negative terminal.

[525i winter driver]

EDIT 2: Apparently the balance and fader is reversed, but it still works. I got the wiring correct according to the Blaupunkt manual and the bmwe34.net diagram, so I can't figure out why its reversed yet still works perfectly.


i think that's because your spkr 'grounds' aren't connected.

i'm not sure exactly how it works but as i understand it the 'grounds' aren't actually grounds they are the completion of a circuit that starts at positive out goes to spkr and returns to the unit via 'negative out'. the speaker needs this circuit to be complete to behave accordingly. the circuit completes itself when you tie the grounds together but i'm pretty sure that although you can move the balance L and R you are listening to a mono source.

not sure... i have to spend a bit more time on it and i was replacing an aftermarket stereo that didn't work (holy nightmare), but i had the same balance and fading problems as you until i connected the 4 brown spkr 'grounds' that are tied together behind the stereo - it took forever to get it right.

thanks for posting your results to date, this is helpful to me too.