Radio Wiring and Amp Bypass

[StereoInstaller1]

This is driving me nuts. I have a JBL Arsenal that I'm trying to install in place of the 1996 crappy aftermarket CD player that someone put into my car.

It is a premium sound 1988 325is with 4 pairs of wires into the fader and an amp in the trunk, but the wires aren't the same colors as the ones mentioned in the OP. To complicate matters the previous owner cut 4 of the wires coming from the fader and connected them to the old head unit. The fader oddly still worked with the new head unit installed. The wires in the trunk are the right color for the speaker wires but there are some other randomly colored wires just hanging out. I might need to seek professional help with this...

Nah, there is an easier way on your car.

Pull the left kick panel, look for a 4 pin plug with yellow and blue wires on it. Those are your rear speaker wires. Cut them and run new wire the 3' or so to your deck. That should have the rears up and running in about 4 minutes.

Beware, the black stripes (from the car, not your deck) are positives!

Now, to do your fronts: use the 4 wires in the dash (they were connected to the fader originally) that are yellow/red, yellow/black and blue/red and blue/black. Those were the 4 positive wires that ran to the amp.

You will need to re-purpose those wires by connecting them to the front speaker wires that are connected to your amp, the 2 grey pairs. Look up the colors on the chart at the top of this post. Cut them near the connector and connect them to the 4 you will be re-purposing, and then the fronts are done.

[mikeb23ft]

Removed aftermarket alarm system, and the panel under the wheel and the speaker cover. Not seeing said 4 port plug, the wiring bundle from the fader just goes on its merry way over the rocker panel by the seat and presumably back to the trunk. Help?!?

[ethorpe]

First I'd like to say thanks for writing this up. I was afraid to tackle this myself but after some careful reading and attempting to figure out exactly what system I have, I've now got a plan of attack which I'll be attempting tonight.

I'm just looking for confirmation that I'm on the right track here.

The car is a 1987 325e, Premium Sound system w/ Fader in the dash. As my colors don't match up to yours and my fader has 6 wires instead of 8, I assume that I get to do new wiring (yay!). I will be removing the stock amp as it doesn't function.

From this thread, I guess my best bet would be to re-run the wiring to the front speakers, and re-use the four positive wires from the Fader -> Amp as rear speaker wiring, ensuring that I match up the correct colors from one side of the amp to the other.

The other option I see is simply run 4 pairs (8 wires) from the deck all the way to the back, and hook them up to the corresponding speaker wires where they output from the amp...

Just want to make sure I've got this all figured out correctly before I really dive into it. I've consulted the ETM to figure out power/gnd/ant for the deck.

Thanks in advance for any advice!

[JGE30]

85 325e it has sound all 4 fader still works

[German Audio Specialties]

Blue/Blue Brown Right Channel
Yellow/Yellow Brown Left Channel
[ATTACH]53970[/ATTACH]

laaaaaame...

OK, you are going to need to do some work on that.

Now that I see your codes properly, you are in no danger of blowing anything up, but you are only using 1/2 the power your deck actually makes.

Read every stupid post on this thread and I bet you figure out what to do.

BTW, the easy test for the moron move your PO/installer did is that the fader on the deck does not work. If you fade to the rear, you have no sound at all, right?

hey man, will this tutorial work for this car? I've got an Alpine head unit to hook up in my 1989 325i coupe. Also, I was told by my local audio install shop that I will have to replace all the stock speakers because they are grounded out seperately and not through the radio or something, and also that there is no radio harness adaptor; are these things both true? thanks! please PM me.

As is typical of the idiots at car stereo shops, they are talking out their ass.

I know, I worked with other shitty installers for over 25 years in those same kinds of shops...pure and simple, most installers suck, they are wrong.

You too need to read ALL of this thread, maybe even download the electrical troubleshooting manual from www.wedophones.com so you can see the actual BMW wiring diagrams.

Pay specific attention to the color codes that go into the amp and into the fader, you will see a continuity of design. Complex is a nice word for it, but once you understand, it really does make sense.

Everyone repeat after me: BMW radios are common ground but the speakers are not, especially if they are amplified. They share a negative, but it is not chassis ground. The deck is what makes it look like common ground. Change decks and "unshare" the speaker negatives and all is good.

And, no, there is no "plug and play" option. If you want quality sound in your E30 plan on doing some work, plain and simple.

Good luck, guys!

Luke

[Badgtho]

The car is a 92 Mtechnic2 appearance
It has no dash fader
It has door tweeters so i assume an amp.

When i got the car it had some really crappy sony radio in it. the guy used miles of wire and some sketchy OEM interface and it only made sound from 2 speakers.

i tore it all out and got my new pioneer to power up, operate the antenna, retain power for the clock.

There was a harness (don't know if it was aftermarket) that plugged into the speaker harness in the car. it jumped a few pins and gave me one yellow and one blueish wire. i thought great, this jumps everything so i have 2 inputs for all speakers. wrong! i was getting sound from the tweeters only; just like the sony that was in there with the rats nest.

I eliminated this jumper deal and i got all to work without using any of the speaker grounds off the new deck. i just clipped and capped them. I sent each speaker positive from the deck to a wire on the car's speaker harness.

it works well and i get sound from all speakers. sounds awesome but i get a little pop when i shut the key off... no big deal.

i was wondering if what i'm saying sounds OK to you and if you can confirm that pop is the stock amp. any way to elminate the pop?

[GunMetalGrey]

Feeling pretty silly here, I am usually okay at wiring but I cannot seem to get this one, it looks like someone tried to clean up the wiring and messed something up? Had a stereo in it when I purchased it but it didn't play anything and I wanted the amp deleted so I figured I would try to knock out two birds with one stone.
Wiring at HU

Wiring at trunk

What I took out

Car is an 89 325is with premium sound with no fader.
I have the same speaker wires in the back as I do in the front, and then the other bundle of non twisted pairs I cannot seem to get any speakers making any noise off of those wires.
Am I missing something or just plain screwed lol

[ProjectCab]

Installing my new deck. '88 with the fader and amp but with aftermarket deck already installed. Any idea why the PO would have spliced both white wires to the blue/white from the aftermarket harness? I'm guessing my amp is still running the speakers?

[Ervin87]

Hi everyone,

It seems that most of this thread is tailored for cars with premium system and an amp.

My 1989 325i coupe does not have the premium system (no amp in the back) but does have a fader.

With the wires that I see, there are 4 sets of wires (white and white/red), totalling to 8 wires.. 3 sets of wires are routed from the driver side and one set is from the passenger side.

Then I have the standard wires, black, blue, yellow, white, blue/white.

While I was reading this thread, my friend used the white and white/red wire sets and connected them to the stereo harness. Surprisingly all the speakers work. He didn't do anything with the wires that go to the fader! Even though the speakers work, I am not convinced that its wired correctly.

What are the fader wires for then?
what are the white and white/red wires ? (+/-) for eatch speaker?

Any advice would be appreciated.

Sorry for all the questions. This is all new to me.

[CB-M3]

i have the premium sound deck and tweeters but no premium wiring? that's odd.

I have a 1991 318is, no fader, Head Unit is CM5908. It has rear premium speaker deck and tweeters.

[BlueBMW]

I just completed the head unit replacement in my 88 325i vert. It had the fader on the dash and that small amp in the trunk. Someone had installed an aftermarket head unit but ran it all through the stock fader / amp. Upon its removal, I found a rats nest of wires going everywhere. After pulling the fader out and following the wires back, I discovered that I only had four wires for speakers. I repurposed those wires to run the rear speakers and ran new wire for the fronts. It came out awesome!

Basically I made a chart to remind myself of which wires were going to be used for what purpose. Then I just cut and connected the wires at the stock amp connector in the trunk.

Left Rear Speaker:
(+) Radio: Yellow/Red ===> Amp: Black/Red
(-) Radio: Yellow/Black ===> Amp: Black/Violet

Right Rear Speaker:
(+) Radio: Blue/Red ===> Amp: Black/White
(-) Radio: Blue/Black ===> Amp: Black/Brown

Here's the wiring at the stock amp connection in the trunk:



The previous owner had installed some nice MB Quart components in the front, so the system sounds fantastic now! Again thanks for all the great info in this thread!

Some more pics of my dirty interior:

[BlueBMW]

Allow me to clarify.

I completely removed the fader knob and used four of the wires between the fader and the stock amp as pos and neg for the two rear speakers. The connections at the stock amp connector were done to complete the connection to the speakers. I ran new wire to both front speakers from the head unit. I did not use any of the stock wiring of the front speakers. So in the end there are 8 wires for speakers coming off the head unit.

I was just trying to show how I repurposed the stock wiring on a 4 wire / fader in dash car that didnt have the twisted pairs further back in the harness. In the end, the fader is gone, the stock amp is gone, and new speaker wires are installed for the front speakers. Rears are wired using existing wiring.

The deck that was in the car when I bought it was wired through the fader / stock amp and was only using two channels of power. That seemed silly to me. After installing this deck and using all four channels without going through the stock fader / amp, the sound quality has gone up immensely.

Sorry about the confusion.


Here's a complete list of how everything is connected.

Deck Connections:
Car ---> Deck
Red/Green ---> Yellow (12V Const)
Violet/White ---> Red (12V ACC)
Brown/Black x2 ---> Black (Ground)
Gray/Red ---> Orange (Illumination)
White ---> Blue (Antenna On)
White ---> Blue/White (Amp On)



Speaker Connections:
L/F + R/F speakers: New Wire directly from deck to speakers

L/R:
Speaker + ---> Black/Red ---> Yellow/Red ---> Green (L/R +)
Speaker - ---> Black/Violet ---> Yellow/Black ---> Green/Black (L/R -)

R/R:
Speaker + ---> Black/White ---> Blue/Red ---> Violet (R/R +)
Speaker - ---> Black/Brown ---> Blue/Black ---> Violet/Black (R/R -)

[redhotchilipepper]

Could someone tell me if this will work okay in my non-premium '85 318i?

All stock wiring, as follows: (behind the dash):
A single Yellow/brown (left side ground, I believe)
A single Blue/brown (right side ground, I believe)
Yellow/red (FL +)
Blue/red (FR +)
Yellow/black (RL +)
Blue/black (RR +)
The usual power, memory, and illumination wires
Fader, which I bypassed and removed a while ago to put another switch in the dash

Alpine CDE-9845 head unit
Stock 5.25" front speakers (non-premium I guess?)
Premium "boxed" speakers on the rear deck (from junkyard)

I am about to install a Planet Audio 1800.5 amp and LukeBox with an Infinity 1062w subwoofer. I read through the 13 pages of posts and it sounds like i need to use the rear stock wires for the rear speakers, and run new wires for the fronts. HOWEVER: why can't i cut the 2 pairs of rear wires at the "halfway" point behind the back seat and then use the rear half of my split to power the rears, and the front half of my split to power the fronts (rear wires connected to front wires behind the dash)? That way I don't have to run as much new wire! Thought I'd ask you pros before attempting.

[StereoInstaller1]

Why do you think this car is special? You have an early, non-amplified "standard" system with the fader in dash. Somwhere in this thread you will find several others posting the same setup and how to fix it.

What exactly are you installing?

Luke

[Vdubmt]

It seems that everything that I find says that the fader will have 8 wires with a splice about a foot back. I've been searching through the thread looking for something similar but no luck yet. Still looking. Installing a Kenwood kdc-200u. Thanks.