Radio Wiring and Amp Bypass

[george graves]

So, this might help a bit. But some amps don't play nicely with shared grounds - or different ground on the speakers vs the amp/deck. And the "factory fader" can be a know problem. But as you said, it was cut out, but perhaps the wiring was the issue? It's too early in the AM for me to think ;) Hope that bit of trivia helps!

[HEIS83]

Stock amp is on the driver's side of the trunk, on the back side of the wheel wel, under a carpeted panel. Did your car had a "fader" in the dash?

Yes there is a fader in the dash, but PO had an aftermarket stereo and the fader wires had been cut. What is strange is that the new speakers/head unit worked great for a few months and then crapped out randomly one day. ill double check the trunk again tonight and see if I can track the amp down.

In researching I didn't find any fuses that would be related to it and if one was and it went, then the whole stereo would go.

[george graves]

Stock amp is on the driver's side of the trunk, on the back side of the wheel wel, under a carpeted panel. Did your car had a "fader" in the dash?

[HEIS83]

Did searching but can't seem to get this resolved so hoping you all can help. I have an 86 eta with no amp that i can find in the trunk. Aftermarket headunit and new speakers install went fine but a few months down the road the quality dropped one day drastically, to the point of some speakers not working at all and the ones that did the quality was awful. I thought it was the headunit but had it tested and it checks out. checked all the speaker connections and they look good, and due to the fact that multiple speakers went out at once, that ruled out one of the speakers going bad.

any advice on this? if there is a stock amp that has gone bad, i have torn the trunk apart and still can't find it.

[TeXJ]

trying to put a Pioneer head unit(DEH-X6900BT) into my 90 325is car. The car had an aftermarket head unit in it before and they cut the factory harness. So I'm trying to figure out what wires from the radio harness goes to the car harness. From all that here, is what I'm seeing:
Body harness:.......................Radio harness:
White(two wires)...................Blue/white(system remote control)
Brown/blk.............................Black
Violet/gray...........................Red
Gray/red..............................Orange
Red/green............................Yellow

I think the above are right...

For the speakers I have
yellow/brown
yellow/blk
yellow/brown
yellow/orange(maybe red?)
Blue/brown
blue/black
blue/brown
blue/orange(maybe red?)

Radio harness has these:
green
green/blk
white
white/blk
purple(violet?)
purple(violet?)/blk
gray
gray/blk


Any help would be greatly appreciated.

[mach schnell]

Here's the wiring in my June '87 built E30 2-door with Premium sound (door mirror tweeters)....







I don't know what head unit originally came in this car.

Which of the many configurations is this one? I'm a rookie when it comes to car stereo...

Also, my E30 has a secondary BMW harness plugged into it right now, that allows a CD43 to plug right in. So that's why it may look different to you.

I'm looking for a pin-out on this car that tells me what the purpose of each wire is.

Thank you!

[b1800e30m3]

Well got the stereo to stay on with the head light. Had a wire hooked up wrong from the head light dimmer. Still no sounds from speakers I'm thinking maybe bad headunit?

[b1800e30m3]

Even worse, when I turn my lights on the head unit goes off still don't have sound either but my Bluetooth speaker is working great till I get this figured out

[b1800e30m3]

What I'm confused on is if I need to run wires to the front lower panel speaker and redo my wiring at head unit so i power rear speakers?

[b1800e30m3]

I removed the oem amp and did the bypass per insructed in this post.

[parkerbink]

There is an oem amp in the trunk.

[b1800e30m3]

Checking now, it's just the amp that's built into head unit. Looks like a micro 10 amp, pulling and replacing it now

[parkerbink]

Check the fuse to the amp, failing that check the amp.

[b1800e30m3]

Just tackled this for the last two days, car is a 1990 318i convertible with premium sound.
I followed bypass for the amp and have all my wires in the back connected to each other:

blue/red-grey/white, blue/brown-grey/brown, yellow/red-grey/red, yellow/brown-grey/violet, blue/black-black/white, blue/brown-black/brown, yellow/black-black/red, yellow/brown-black/violet.

then at head unit i have everything like op posted except one white wire going to amp that is not there is not connected and brown/black wire which i don't know where it goes? head unit powers up radio receives a stereo signal but no sound out of any speakers. PLEASE HELP

[thexfactord22]

Just did this today....This thread is bad ass, once you peel back the tape and find the wires twisted together its super easy!