Radio Wiring and Amp Bypass

[tkeenan]

How hard is it to pull the front speaker wires that come from the amp, separate them from the loom of wires, and then rewire them directly from deck to front speakers?

[s1uma1]

Hi Guys. i have a 91 318is. Non-premium audio. Original Alpine Headunit (slider unit). I recently wired up a pair of premium speakers for the front (tweeters and mid drivers). Hooked everything up and it sounds like absolute ass. I read through this entire thread "Radio Wiring and Amp Bypass", but seems like mostly directed at premium audio folks. Saw a few posts were it was stated 91 Base systems should be very easy. Trying to figure out if 1) wiring issue 2) speaker issue 3) head unit issue.



Here's the back of my head unit... and i labeled what i think the wires are:


Here's how the tweeters are wired


so when i hook up the speakers correctly into the headhunt, i have almost NO sound coming from the front. Rears sound great. The fade/balance function on my headhunt does crazy things... fading to front cuts out front volume, but i still hear rear speakers.

When i REVERSE the connection, (front wires to rear output and rear wires to front output), the fronts have sound, but sound like ass. mid bass driver is firing, tweeters are going, but little to no bass and easily distorts at moderate volumes.

Any suggestions/advice?

[StereoInstaller1]

87 Vert means you need to run new wires to the front speakers and re-purpose the input wires to the rear speakers

[AngeloF10]

There are 8 wires that come out of the fader, two of which are the yellow and the blue I mentioned above. No twisted pairs anywhere. Now I am really losing it

[AngeloF10]

Forgot to mention. '87 e30 vert. I have a fader in the dash and tweeter on the door

[AngeloF10]

Attempting to install a Kenwood KMM-BT315U. PO had a benzibox installed so the stock wiring harness is pretty hacked

From the car I have brown\black, violet\gray, yellow, and white.
I also have further up the harness a random white that wasn't plugged in to anything and then a red\green and a red\gray. All of these wires were connected to the best harness and everything worked, like sh!t. Lol

So now I am a little confused as to what to connect.
I think I should have
Kenwood harness------ car harness
Black------brown\black
Red------ violet gray
Yellow------ yellow
Blue\white (labeled ant.cont)------white
Brown(labeled mute)----- nothing
Blue\yellow(labeled steering)------ nothing

But then I have a blue wire that I don't know what to do with.
And also the white, red\green and red\white further up the harness.

I believe after I get this sorted out I still need to connect the speakers. Although I have no idea how the speakers were working on the benzibox. I do plan on bypassing the amp if that is still recommended.

Thank in advance for any help

[actletpone]

The wiring is capable of supporting it, upgrade your fuse to 15A.

BTW, most are 10A if I remember right...

The electrical trouble shooting manual says the "(+12V ACC) Red-------------Violet/White wire (Changes to Voilet/Grey at C302)" is 18 awg.

Is 18 AWG not too thin for a radio with 15 Amp fuse + the obc and whatever else is on the same circuit?

[StereoInstaller1]

The wiring is capable of supporting it, upgrade your fuse to 15A.

BTW, most are 10A if I remember right...

[actletpone]

"(+12V ACC) Red-------------Violet/White (Changes to Voilet/Grey at C302)"

Correct me if I am wrong but this wire is rated for a 7.5 Amp fuse. Most aftermarket radios today require more power due to their internal amplifiers.

The one I want to install requires 15 Amp. Can you tap into the unused fuses (25 + 26) in the fuse box or should you run a power wire straight to the battery? Unfortunately I do not have the auxiliary fuse panel.

[Jdub]

So 4 more sources of power = tweeters, front speakers, rear speakers, and sub? And what purpose do RCA wires serve? Sorry these are probably very stupid questions but I'm trying to learn as much as I can from someone as knowledeable as you.

Here's what I did today:





I pulled these two things out of the picture just above it, I'm not sure what these two are.



Here is the main source of wires coming from the dash to the amp? So I need to identify which ones to cut and extend with the roughly 3' of other wire you mentioned right?

After reading the thread again, I think I understand that these colors you mentioned are the ones that need to be cut?

RF+ Grey/White
RF- Grey/Brown

LF+ Grey/Red
LF- Grey/Violet

RR+ Black/White
RR- Black/Brown

LR+ Black/Red
LR- Black/Violet

Thanks for being patient with my ignorance.

[StereoInstaller1]

Wow thats a bummer to hear, but I appreciate all that youve done for the forum.

If you were me, (I have a 12" kicker sub and an audiopipe 1000 amp in my garage) would you go ahead and set it up for the sub and amp system from the start? I guess all I would have to do is buy one of your boxes and wire it up right?

How does that change what I need to do with wiring? Im most concerned with breaking all the little tabs you talked about when I pop off the door panel to run wires, is it easy to buy new replacements?

This mighr be a super stupid question but I want to make sure i know what you mean when you say sub level control. Does that mean the little nob that controls how loud the sub is? I used to have one of these under my steering wheel in my integra.

If you were to amplify all the speakers, you would run 3 sets of RCAs and use the wiring from the stock amp for the speakers, then of course you would need 4 more channels of power.

[Jdub]

Wow thats a bummer to hear, but I appreciate all that youve done for the forum.

If you were me, (I have a 12" kicker sub and an audiopipe 1000 amp in my garage) would you go ahead and set it up for the sub and amp system from the start? I guess all I would have to do is buy one of your boxes and wire it up right?

How does that change what I need to do with wiring? Im most concerned with breaking all the little tabs you talked about when I pop off the door panel to run wires, is it easy to buy new replacements?

This mighr be a super stupid question but I want to make sure i know what you mean when you say sub level control. Does that mean the little nob that controls how loud the sub is? I used to have one of these under my steering wheel in my integra.

[StereoInstaller1]

I've been reading through all of your threads for a couple hours now Luke, and I think I have an idea of what to do, but I am absolutely a newb when it comes to electrical. I have an 89 325is (with tweeters, so I think its premium)

When I turn my radio on, there is incredibly loud static. I assume that means a toasted amp. My plan is to bypass the amp, and put in a new head unit like you said.

My question is, if I do proceed with this technique, but want to eventually add a sub in the back (using your technique in the thread about making an awesome setup for $500) is it going to be an easy addition?

It makes me nervous as hell cutting wires, Im going to go tear apart my car in a second and take out the amp and the HU and see if things start to make more sense. Im guessing when I take out the amp the wiring will make more sense, but I think I understand: There are wires that go INTO the amp from the HU, and then there are wires that go OUT of the amp to the speakers. When we "bypass" we are simply using the power from the new HU instead of the amp, and then cutting and connecting the wires the go from the HU to the amp, directly to the speaker wires?

PS. What is a fader and why is there a wire for it? (forgive my ignorance)

First, as with everything I build, my goal is always to have an upgrade path, so yes, adding an amp later is pretty easy. In fact, since you already will have all 4 pairs of speaker wires and the "remote" (amp turn on) wire already in the trunk, its easier than most cars. You still have to run the RCA cables, still have to run the sub level control too, if the amp you choose has that capability (it should).

Now, lets talk about the deck swap: you have to run wires for that in an 89, even with premium. Its absolutely necessary to have 4 pairs (8 wires) of speaker wires, you only have 6, so the easy thing to do is just run new wires to the fronts.

The only issue there is to amplify it you have to un-do that and go back to the original wires, but since you would be the one putting them in, that should not be too tough.

Furthermore, due to issues beyond my control, we will be closing down in a few weeks. We have already begun the process, the decision is final and I have no plans to continue in the car audio field after we shut this down.

In the meantime, we do have boxes on the shelf ready to upholster and ship, plus we will be building more in the coming weeks.

Thanks, and I hope that helps.

Luke

[Jdub]

I've been reading through all of your threads for a couple hours now Luke, and I think I have an idea of what to do, but I am absolutely a newb when it comes to electrical. I have an 89 325is (with tweeters, so I think its premium)

When I turn my radio on, there is incredibly loud static. I assume that means a toasted amp. My plan is to bypass the amp, and put in a new head unit like you said.

My question is, if I do proceed with this technique, but want to eventually add a sub in the back (using your technique in the thread about making an awesome setup for $500) is it going to be an easy addition?

It makes me nervous as hell cutting wires, Im going to go tear apart my car in a second and take out the amp and the HU and see if things start to make more sense. Im guessing when I take out the amp the wiring will make more sense, but I think I understand: There are wires that go INTO the amp from the HU, and then there are wires that go OUT of the amp to the speakers. When we "bypass" we are simply using the power from the new HU instead of the amp, and then cutting and connecting the wires the go from the HU to the amp, directly to the speaker wires?

PS. What is a fader and why is there a wire for it? (forgive my ignorance)

[StereoInstaller1]

I want to thank Stereoinstaller1 and other members who posted their setup. Followed the instructions (90 M3 w/ premium sound system) as noted. Removed the stock alpine CM5908 and installed a CD43 (M logo) using the OEM amp and speaker system. Followed the instructions to the T and it woked out great. Used the CD43 BMW factory 4 channel harness from ECS tuning and did not connect the 4 negative speaker wires to the CD43. Connected all negative speakers to ground chasis and it worked out great. So happy that no wire hacking was needed. all stock wires used. Again, THANK YOU!!!!

Awesome! Good to hear, for sure