New Head Unit/Radio wiring problem (1990 535i)

[SpazE36]

After searching on here and reading a good deal, I am still in need of some guidance... I am hoping Luke ,

Stereoinstaller1

, will chime in as all of the post/threads I have researched he is very knowledgeable.


Car: 1990 535i (it's my understanding that pre-1991 you can't use the handy adaptor " metra 70-8591 ")
Head Unit: Kenwood KDC-258U (Cheap simple head unit)




I bought my car and it had a nice BMW cover over existing radio 'hole'... I assumed that the stock unit had been pulled and cover placed there to keep things tidy...
Ohhh no, little did I know that a previous owner pulled out what I assume was an aftermarket head unit. All I have to work with are the original plug/wires cut and elec. taped off :/



I am trying to make sense of the cut wires with the info from BMWe34.network
zz1 by Caleb Henley, on Flickr





This is the main glob of wires...

Using a multi-meter I was able to figure out what I believe to be...

Switched power +12v: White with purple stripe
Ground: Two- Brown/tan stripe wires and one-brown wire all crimped together to one black wire

The rest I have no idea...
White wire
Blue wire
Yellow wire
Black/white stripe wire

zzz by Caleb Henley, on Flickr










This was a small two pin plug with yellow and white wire... researching these forums I believe that this yellow wire is the constant +12v... correct?
zzzz by Caleb Henley, on Flickr




Antenna
PhotoGrid_1453920157192 by Caleb Henley, on Flickr




I believe this is the plug going to the AMP??
PhotoGrid_1453920194508 by Caleb Henley, on Flickr



This plug goes to the CD changer in the trunk...?
PhotoGrid_1453920177286 by Caleb Henley, on Flickr


I was able to get my new head unit to power up using the +12V constant/ +12V switched and the Ground (two brown/tan and one all brown wire).... but using the speaker out (+) from the head unit I was unable to get any sound from anything/any speaker...

[rxline]

Shit man,

I just installed one. Red is power, Black is ground lol. it looked like it had been butchered multiple times. I just got it so the CD worked and touched wires until I knew what was what. Seemed like the tweeters and front speakers were tied together. Not the right way of going about it. Good sound up until about 32/50 sound setting on stock speakers. Then it gets crackly

[SpazE36]

Shit man,

I just installed one. Red is power, Black is ground lol. it looked like it had been butchered multiple times. I just got it so the CD worked and touched wires until I knew what was what. Seemed like the tweeters and front speakers were tied together. Not the right way of going about it. Good sound up until about 32/50 sound setting on stock speakers. Then it gets crackly

That's similar to what I tried... got the head unit powered up and then touching speaker outputs from head unit with various wires left to see if I could hear anything from any one of the speakers....not in any means do I recommend that lol

[E38740iMD]

I wish I could help. I'm a Mecp stereo installer but I forgot what's what. I at first hooked up the left and right input to the factory amp but now I completely bypassed the whole thing with amps and crossovers. I may still have the wiring if and don't my job if it helps.

[kalevera]

You can make this work (right now a possible reason why you don't have sound, assuming the factory amp is still connected, is because the amp isn't getting the power on signal from the white/remote power wire), but there's two options that might make more sense for you:

1) BMW sells (or sold, as of a few years ago) a pigtail adapter harness to convert the pre '91 E34/E32 harness to the post '91 universal connector. It's in ETK

2) or, you could ditch the pre '90 wiring harness altogether, source a '91-'92/3 harness and replace the entire thing....Here's why this might be a good option for you -

I believe this is the plug going to the AMP??
PhotoGrid_1453920194508 by Caleb Henley, on Flickr

That's the subharness connector for the speakers. Because it looks untouched (and everything else is cut), chances are good that you'll be repairing other parts of the harness that go to the speakers, and you may be better off doing the upgrade while replacing it

[SpazE36]

I started with my DMM and found grounds and constant +12v and the switched +12v... also the amp power +12v (switched/small power signal) and figured out all the different speaker wires... after 3 hours and printed off wiring diagrams and various threads from here...

I will post another thread for pre-1991 e34 wiring .... possibly a DIY' thread(asking mod's for advice here...) listing all the wire colors and what they are when I have time.


Anywho here it is all done sorry for the crappy pics I was tired and ill after it all haha

It sounds O.K... for time being for 26yr old stuff haha, I will put a decent amp and component speakers at a later time

Start

PhotoGrid_1454076537798-1 by Caleb Henley, on Flickr




Finish... even got the LCD color to match the factory BMW orange sort of... I'm happy

PhotoGrid_1454076492970 by Caleb Henley, on Flickr

[E34schindewolf]

What wires are what? Im about to do the same install on my 1990 535i