Radio Wiring and Amp Bypass

[StereoInstaller1]

I am not 100% sure with early 'verts.

The big trick is you have to have 4 pairs from the deck to the speakers.

Check your amp input plug, see if you have 5, 6 or 8 wires from the deck to the amp.

[ScottSneed]

Radio Wiring and Amp Bypass

Ok. Was hoping to not have to do all that due my limited time, but sounds like I have no choice. Based on what I've read so far, it looks like if I do what BlueBMW did I should be good.

Since he had what I have (4 wires with no twisted pairs), it seems that his setup is what I need to do:

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)

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

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 -)

If I understand this all correctly, basically, all the wires I have connected to the deck's speaker wires right now will become the pos/neg rear speaker wires, and I run new ones to the fronts. Assuming that this is correct, my only other question involves the door tweeters. Do these simply go away, do I run a pos/neg from the front speaker stereo wires to both the footwell speakers AND the tweeters, or do they get powered somehow through all the magic involved in the new connections in the trunk? I've seen a lot of reference to them with regard to determining what type of system people have, but nothing so far with regard to powering them once the bypass is done; only re-wiring the kickpanel speakers. Maybe I missed something?

I have followed this and got my rears To work perfectly (88 cabrio as well). However, my question is do I NEED to run wire to the front speakers or can I do the same with the front speakers? Also what wires would I need to tap into?

[e30blitz]

Crimp is far the easiest

Solder and heat shrink
Is cool and thin. When installed

But get a pack of butt connectors
And crimp away :)


OO ||| OO + O w O

[NeedaE30]

questions..

I am starting this project after the previous owner has hacked all the wiring.. i I have removed the oil covered aftermarket amp from the trunk tons and tons of wires just dangling around it and it certainly did not work.. the HU powered up but never had any sound... Fader switch has nothing at all connected to it missing left rear speaker. Pulled head unit out of car and found 2 wiring harnesses.. the factory harness hacked up and the aftermarket harness also hacked up... thick gauge aftermarket speaker/sub wires inside the dash but not connected to anything.. i dont even know where to start... I'm pretty sure since the fader is not connected and there was an aftermarket amp in the trunk, that the factory amp has already been bypassed.. I'm literally about to tear out my entire interior and start to try and figure this out ill take pictures as i go but if anyone has any suggestions please chime in.. i'm a newb when it comes to car audio

Printed first post to use as reference


couple pics of what im working with

Found this dangling inside the dash with only 1 wire connected it's heavy and looks to be from 1983 lol






also can i solder and heat shrink my connections without issues? or is it recommended to use crimp connections? which i dont have lol

[luckydog2]

thanks for the wiring tried and worked but on a kenwood with blue tooth I used the amp and it works yes it does thx again

[DaKine]

Finally I have a head unit hooked up. I bought my 87 325i with premium sound but no head unit. I figured out how to hook up the speaker wires thanks to this thread. I ran new speaker wire to my fronts and used the fadder wires for the rears. I really don't think I'd of done it as clean and frustration free as I did without this thread.

I was really surprised by how well the stock rear speakers sounded. The left front is shot and the other is alright. Didn't get the tweeters to work but I'm planning on buying new speakers to set that up properly.

I am very pleased and just wanted to say thanks!

[StereoInstaller1]

Well, not sure what took the last 5 hours of my day, but:



Sorry for the blurry-cam, but the new head unit is in and sounds amazing.

Luke, I know you get this all the time, but you were so incredibly right. About everything.

Getting rid of the amp and fader made everything better. I don't think my previous HU was that bad (it was really badly setup and connected), but just connecting the speakers directly to the HU fixed everything.

I thought my tweeters were bad. They weren't, they sound awesome.

I thought in general my stereo was weak and my car just got bad radio reception. False. Stock amp was filled with sand (from when I had the car stripped, sandblasted, and re-painted). The stock amp also has been made obsolete by modern technology.

I added a ground cable directly to the back of the headunit and my radio reception seems to be amazing (after writing this I remembered that I also ran a new antenna cable, so that probably had something to do with it). That said, I haven't tested it too much. I haven't driven anywhere and my new HU has HD radio, so of course everything I was listening to sounded better (lots of HD radio in the DC area). Thinking about it, I was able to get in stations that I usually don't get from the house, so I am cautiously optimistic.

Anyway, I am so glad I did this. It isn't that hard, and it was a Sunday well spent, even if the lawn didn't get mowed.

I still have to get some blanks to fill in where I pulled the fader and I'm going to pull that dumb window switch the PO put in there that is wired to the locks. I'm going to copy the mic-in-the-blank mod that someone did.

Next up, putting in my e36 window switches and vaders.

Ooh yeah. Vaders. After that is done I might never leave my car.

Well hot damn...first, thanks!

Second, I don't ever get tired of hearing I got to help someone, thanks again.

Third, sounds like you are almost ready for a subwoofer!

Congrats, man, good job.

Luke

[FastAndLight]

Well, not sure what took the last 5 hours of my day, but:



Sorry for the blurry-cam, but the new head unit is in and sounds amazing.

Luke, I know you get this all the time, but you were so incredibly right. About everything.

Getting rid of the amp and fader made everything better. I don't think my previous HU was that bad (it was really badly setup and connected), but just connecting the speakers directly to the HU fixed everything.

I thought my tweeters were bad. They weren't, they sound awesome.

I thought in general my stereo was weak and my car just got bad radio reception. False. Stock amp was filled with sand (from when I had the car stripped, sandblasted, and re-painted). The stock amp also has been made obsolete by modern technology.

I added a ground cable directly to the back of the headunit and my radio reception seems to be amazing (after writing this I remembered that I also ran a new antenna cable, so that probably had something to do with it). That said, I haven't tested it too much. I haven't driven anywhere and my new HU has HD radio, so of course everything I was listening to sounded better (lots of HD radio in the DC area). Thinking about it, I was able to get in stations that I usually don't get from the house, so I am cautiously optimistic.

Anyway, I am so glad I did this. It isn't that hard, and it was a Sunday well spent, even if the lawn didn't get mowed.

I still have to get some blanks to fill in where I pulled the fader and I'm going to pull that dumb window switch the PO put in there that is wired to the locks. I'm going to copy the mic-in-the-blank mod that someone did.

Next up, putting in my e36 window switches and vaders.

Ooh yeah. Vaders. After that is done I might never leave my car.

[FastAndLight]

Thanks Luke, I'll let you know.

I'm disappointed with myself because I went all cheap and just bought some generic metra wire. Please don't hate me forever

I'm back and about to start snipping. Here we go...

[edit]

Well, I reversed power and illum at first. And have run out of crimp connectors. Should have checked that before the last run. Off to buy more and then run the speaker wires.

[StereoInstaller1]

Good Sunday morning project. '88 325iX premium sound with fader.

I started with removing the rear seats, center console, and front ashtray and everything so that I have a clear path to run wires straight to the trunk. I need to run a new antenna cable too because of the PO.



I removed the headunit installed by the PO. It looked like a horrible wiring mess, until I kept pulling, removed the fader switch, and saw that the PO's destruction was limited to the first 4" or 5" of the harness.



I've decided that I am going to remove the fader and its associated wiring and clean up the PO's mess.

I know Luke says that the factory wiring is awesome and to just re-use that. But, to minimize my own confusion, and since I have to run wire to get the fronts to work anyway, I'm just going to run new wire to the trunk for all 4 channels and then bypass the amp.

I feel like that way I will have a better grasp on exactly which wire goes where for the speakers.

I'm headed out to by speaker cable now. More photos later.

Nice! Tear it up, you sound 100% ready to kick its ass.

LMK if I can help

[FastAndLight]

In progress

Good Sunday morning project. '88 325iX premium sound with fader.

I started with removing the rear seats, center console, and front ashtray and everything so that I have a clear path to run wires straight to the trunk. I need to run a new antenna cable too because of the PO.



I removed the headunit installed by the PO. It looked like a horrible wiring mess, until I kept pulling, removed the fader switch, and saw that the PO's destruction was limited to the first 4" or 5" of the harness.



I've decided that I am going to remove the fader and its associated wiring and clean up the PO's mess.

I know Luke says that the factory wiring is awesome and to just re-use that. But, to minimize my own confusion, and since I have to run wire to get the fronts to work anyway, I'm just going to run new wire to the trunk for all 4 channels and then bypass the amp.

I feel like that way I will have a better grasp on exactly which wire goes where for the speakers.

I'm headed out to by speaker cable now. More photos later.

[FastAndLight]

I'm going to be trying this tomorrow in my '88iX with premium sound and fader switch. I've peaked behind the head unit the PO installed, and it is a disaster back there, so I'm going in armed with Luke's guide, the ETM, and my camera.

I plan to bypass the stock amp and just power all of the speakers with my new headunit. For the new wire runs to the two front speakers, can I just use normal speaker cable, like what I use in my home stereo, or is there some special stuff for use in the car?

From the ETM, it looks like the front tweeters are connected in parallel to the speaker in the kick panel. Will I need to do anything special to make sure they are connected when I replace the wiring? My tweeters have been sounding like complete trash recently and I'm not sure if it is the speakers or the wiring (or the amp?), any ideas?

Thanks to everyone for this thread, it is pretty awesome.

[StereoInstaller1]

No, you only have to run wires to the front.

You use those 4 to run the rears after connecting them in the trunk.

[Shurik]

Never mind I think I get it. I just have 4 wires from my fader sending sound to the amp, and there they split into 8 wires running to the speakers? So I wouldn't be able to wire an aftermarket hu without running wires to the back. I will just save up a little bit for the amp + RCA setup.

[Shurik]

I can't seem to find the right thread for my setup, could some one point me to the right place? I have premium setup but with 6 wires coming out of the fader instead of 8. How would I wire this into a new hu harness? Am I going to be connecting the back speakers to the front?