PO disconnected factory stereo, can I get some help to wire it back in properly?

[midnight_marauder]

Hey all, so I just recently acquired a canadian e30. Two owners ago, the PO disconnected the factory stereo to put in an aftermarket deck. Before selling it to the next owner, he removed said aftermarket deck and replaced the factory unit into the slot, but left it disconnected. Although he hacked the wires up pretty good, I'm just thankful the original deck is still there. Still, I need to figure out this mess of wiring so that I can enjoy some sweet tunes. I ordered one of these in the meantime: https://cantalouperadio.com/collecti...stallation-kit

The radio is a KE81ZBM-02, here are pictures of it: https://imgur.com/a/nt2LzX7

I found a box of factory(?) stereo wiring included in the sale all jangled up and I'm struggling to make much out of it. I identified the main harness that contains the 12V, ground, speaker wires, etc, but I can't find where it should plug into. There's also other random misc wires that I'm trying to make sense of. Can anyone help me figure out what these misc wires are? https://imgur.com/a/YP0FdSk

Finally, where does the main harness plug into? I can't find anywhere within the stereo cavity in the climate cluster to plug the main harness into. https://imgur.com/a/ydI5jRx

Thanks!

[bradnic]

good you have Jay's harness patch connector kit. the KE81 is a 2 channel radio. Do you have the BMW Sound System? comes with a trunk amp and door tweeters.
The speaker/radio/amp wiring diagram for your car can be found here https://www.r3vlimited.com/board/for...and-amp-wiring

buried in your "misc wires" pic is a two to 4 channel harness adapter. The other wires in that box are aftermarket garbage. What year is your E30? Do you have a fader knob below the center AC vents?

[midnight_marauder]

Hey bradnic, thanks for commenting. I've read through your other posts in the past and appreciate your wisdom on e30 wiring/audio.

My 1991 e30 325is came with the BMW premium sound system as a factory option, so I believe so. I remember seeing door tweeters, not so sure on locating a trunk amp, I'll have to take a second look when I get to the car. There is no fader knob below the center AC vents.

[bradnic]

ok if it's a 1991 your car came with a 4 channel radio. that explains the harness adapter in your junk box. the KE81 is not original to your car - all two channel radios require the fader knob in the dash. If want to stay OEM you will want a KE83 or a CM5908. use the 4 channel BMW Sound System schematic on that wiring thread. all wire colors are labeled. the connectors are also identified. you will need to trace the radio harness back to the fader connector and rebuild it. check the sticky thread in the audio forum for more assistance

[midnight_marauder]

Thanks a lot bradnic! I’ll find a CM5908. I’ll take a look at the sticky. Do you know in what direction I should search within the cavity to find existing wires for the stereo to connect to? Just at a loss on whether those were totally stripped out of the car at one point. I’d rather not have to rip apart the dash.

[bradnic]

just head towards the instrument cluster. there's a sticky audio forum post by StereoInsteller1. it's a lot of info but if you read the first few pages and study the schematic I linked you should have what you need to know.

[midnight_marauder]

Hey bradnic, I was able to find the wiring. I plugged everything into a used CM5908 properly with the new cantaloupe radio wiring and also did the amp bypass in the trunk. However, I’m not getting any sound. I fear it might be the deck.. is this something I could ship to you for a fix? It looks like cantaloupe radio no longer offers repair services. I have a video showing what’s all going wrong with the stereo in the car. I know I have a low post count - I’ve read your posts that you ignore PMs from low post count accounts, but hopefully the video will clear up any concern. Let me know and I can send over the video.

[midnight_marauder]

bradnic heres the video. Apologies for shooting in portrait mode and not landscape mode. Hope this helps.

https://youtu.be/X-PuQRBuGdU

[bradnic]

Will take a look

[bradnic]

Great job on the radio vid! some observations

you have some work to do to get the radio and wiring restored, but it's not impossible. It's great you have extra radios to test with - in fact the 3rd radio is actually an OEM pioneer KE83, which is a 4 channel radio just like the CM5908. The radios are electrically identical - the same car wiring works with both radios.

So first things first.

POWER TO THE RADIO
- you already have power to the radio, so that's great

CONFIRM WHERE YOU HAVE SOUND FROM ANY SPEAKERS
- you need to find any wiring or radio channel problems. it's usually one or the other for each channel - sometimes there's a wiring problem, sometimes the radio itself has problems. sometimes both are true.
- since you have no sound from the 5908. Try both of the other radios and find out if you get sound after you enter the code in them. If you get sound the speaker wiring for the channel that's working is probably ok. If you don't get sound from any of the radios most likely your speaker wiring isn't working right.
- if you don't trust the radios you can also just grab any other radio or sound source with a speaker output and just try each of the speaker connections at the headunit.

TESTING WIRING WITH A KNOWN WORKING RADIO CHANNEL
- If you have at least one radio channel confirmed working you can use that channel to test the speaker wiring. So first thing you need to do is try the radios you have and see if you can get at least one channel working. If you do you can use that radio to test all the wiring.

LOOKING FOR SPEAKER WIRING PROBLEMS
- this depends on the factory options per the E30 wiring thread I shared earlier. We've already confirmed (a) you have premium 4 channel sound, (b) your premium amp trunk harness was cut and (3) amp bypass in the trunk appears to be in place.
- for each radio channel, if the radio is working with balance and fader centered, and the wiring is correctly connected between the radio and the speaker then you must hear sound.
- if any of the channels are not working, and you've already tested the wiring for each of the channels, then the radio itself is defective.

RETAINING THE RADIO CODE WHEN POWERED OFF
- try multiple radios with known codes if you can. If none of them retain the code when powered off, then the yellow memory wire is not getting always on power.
- I've seen wiring problems INSIDE the radio too. if at least one of your radios retains the code when powered off then the others have internal wiring issues.

ANTENNA POWER
- there's a single white wire that connects to the back of the radio and triggers the power antenna. in the video of the KE83, the connector you pointed to is the power antenna wire connector. The same style connector is on the back of the other two radios too.

[midnight_marauder]

bradnic

Thank you for the detailed response. Unfortunately, I'm away from the car until the new year - so I will have to wait to test with your advice then. Just bought a cheap speaker at goodwill for testing when the time comes.

Do you happen to know the part number for the plastic harness/wire adapter that plugs into where my finger is pointing at here: https://imgur.com/a/7yZn5c8 for the KE-83? Jay's harness kit does not come with this part (KE-81 and CM5908 have this part permanently fixed to the radio, so I guess it was skipped for Jay's harness adapter). I can't really test the KE-83 without this part, because that's where the illumination power and memory power seemingly comes from.

I will send you a PM about pricing and radio availability. Thanks.

[bradnic]

You don’t have to connect that