Understanding E30 speaker and amp wiring

[PNWE30M50]

I wanted to try and help others in return and thought maybe a video could do that.

Luke's massive original amp bypass thread helped me out a lot. So much reading! I posted over there as well in case others are looking.

I have a 1987 325es, CM5907, premium sound, fader in dash (6 wires), and a stock amp in the trunk. Went with a Continental TR7412UB-OR, bypass stock amp/repurpose fader wires, rewire fronts/tweeters.
Please let me know if you see something I did wrong so I can fix it!!! I am also garbage at talking while filming...so sorry in advance.

Hope this helps someone

https://www.youtube.com/watch?v=lXYdEnJJVnU

[nando]

is it in the trunk next to the antenna just like a sedan? you have to pull the carpeting off the driver's side.

also, is your KE83ZBM for sale? Does it work?

[Scottie409]

Hello, am replacing the head unit on my 91 318i Converible with a Pioneer CD bluetooth unit and removed the KE83ZBM and didn't realize there was an auxiliary amp on this vehicle.
Where is the amp located on a convertible?
thanks in advance
Scottie409

[nando]

yeah, I wondered. I think I left it attached to the radio that I ended up selling for probably $5. Doh! I see it's still available new, I should order one before it goes NLA.

I'd pat myself on the back, but I feel like I dodged a bullet. When I first looked at it again, I had no recollection of how I'd wired it originally and feared the worst (it was almost 20 years ago, lol). But earlier when I was even younger and especially dumber, I cut a huge hole in the hood of my '67 Dodge Dart to put in an ugly hood scoop. Ugh. I regretted it instantly, and ever since then I've had an aversion for permanent, irreversible mods.

It's funny because of course when I originally did this, I didn't listen to tapes - I wanted a CD player, and later MP3s were the thing. The stock stereo I didn't assign any value to. Now I mostly listen to the radio, and I don't exactly blast the tunes. I've had the blank plate for nearly 10 years now, and honestly I'd be pretty happy with a stock, unmolested sound system vs nothing at all. Now I kind of want to make a mix tape of some 1990's music, lol.

[bradnic]

BTW you’re missing the 2 to 4 channel adapter harness. Pic and part number earlier in the thread.

nice job keeping the original connectors and just splicing in the ISO bits for your aftermarket. I did the same thing on my vert years ago so it was super simple to restore it back

[bradnic]

That’s a KE83ZBM 4 channel pioneer. Switch to a 5908 slider and you can rock the Canteloupe BT board. Jay’s not doing them anymore but I am doing another production run later this summer.

[nando]

yeah, it's my ix, it had premium sound - but I have no recollection of what the original stereo was (might be able to find it in old pics). I think I can just repair the wiring, but I might be missing a pigtail/adapter or whatever was plugged directly into the stereo.

actually, I have *one* pic of the stereo (sorta) - from the day I got the car in 2002, lol:

http://www.325ix.com/pics/2002/05-31-02/MVC-272F.JPG

[bradnic]

nando !!!!! damn son. Happy to help get your setup back. this is your IX right? you've got premium sound I think.
if you want the wiring back 100% stock just hunt on ebay. Otherwise I have some of jay's repair connector kits.

[nando]

Man, I fee so stupid for hacking up my original wiring and putting in a shitty aftermarket head unit (long since gone - I've had a blank plug in that spot for years now).

Thinking it might be time to go back to all OE. All of the wiring is still there I think, but I don't remember exactly what I cut and removed. I gave away the stock premium radio for a song too! But it looks like I still have options. I'm pretty sure I left the amp inside the car (I hope!). I actually have a full harness from my '88 ix parts car, but that had been cut a bit as well.

edit: well, apparently 21 year old me wasn't as dumb as I thought. I did cut a couple wires - but I actually left all of the original harness and plugs there. I remember now - ran separate wires from the stereo to the connector in the trunk, so all of the wires to the speakers, head unit, etc are original and untouched.

http://www.325ix.com/photos/cache_big/2021/OE%20Stereo/IMG_2133.jpg
http://www.325ix.com/photos/cache_big/2021/OE%20Stereo/IMG_2134.jpg
(looks like image linking is broken on this forum now, ugh)

The bad part is I can't find the amp (it's not in the trunk). I thought I had it somewhere, but I dug through my giant pile of parts and didn't see it. There's a spider infested box I haven't looked at in years, it might be in there, but it's probably water damaged by now anyway.

At least repairing the original harness should be dead simple! All I have to do is remove the butt connectors and splice the stock wires back together. I'll probably want to pull out those speaker wires I put in, but they aren't hurting anything if I just leave them either.

[bradnic]

just received my power amp connector from RyanBelton . It is very well made and documented. Highly recommended.

[bradnic]

...a class D 4 channel amp could potentially fit in the original amp housing. It’s a lot of work though. You can accomplish the same thing with an amp bypass and wiring in a small commercial class d amp. It does require cutting the harness though. The key issue is sourcing the connector on the amp housing. I haven’t been able to find it yet.

If you can't find the stock amp connector anywhere, you might consider replicating it in CAD and 3D printing it.

There are lots of places to get high quality 3D prints now a days. Stratasys, Xometry, ProtoLabs to name a few.

RyanBelton is offering a 3d printed connector that you can use to make an aftermarket amp harness with.

[bradnic]

ave30rudy did you figure it out? info is in the schematics above. if you ended up with one solid yellow and one solid blue wire unconnected, then you have not connected the head unit to the speakers. From your description it sounds like the two wires are at the trunk amp connector.

[ave30rudy]

so I did all the new head unit wiring, all the speaker wires connected to the new speaker wires, and power etc. Then I have one yellow wire and one blue wire, both coming from the power bundle, not the speaker bundle that have no where to connect to. I went ahead and did the whole amp bypass wiring as well. However I still have no sound. My assumption is that my problem is coming from those two wires in the dash. But my question is where do I connect those?

[CW325]

On an early model 2 channel radio only car would I need a “floating ground adapter” or could I just share the front/rear negatives for each side?

Update: after doing some more research I ran new negatives for the 2 front speakers and left the existing negatives as dedicated rear negatives.

[CW325]

On an early model 2 channel radio only car would I need a “floating ground adapter” or could I just share the front/rear negatives for each side?