Understanding E30 speaker and amp wiring

[B2NTY]

Yo, I'm doing a sound system conversion on my early model. I know my way around e30s but I'm a complete rookie when it comes to wiring and audio. It came with a non-premium system and I'm upgrading it to a late-model premium system with a cm5908. I currently have the late-model rear speakers and tweeters, the front tweeters, and the Blaupunkt amp. I need to get a hold of the front footwell speakers to figure out the wiring. I've been looking for the OEM wiring harness I need (which I believe is 61-12-1-381-719). However, when I found a guy doing a part out with the late-model premium system and talked to him he highly recommended doing aftermarket wiring instead. Everything in the setup would be OEM late model premium and I wouldn't mind having the OEM harness but I'm also open to doing aftermarket wiring because I think it would be a fun thing to do (I'm aware that it is a difficult thing and can be a pain but I like that stuff :) ). I plan on using cassette tapes and making my own mixes using a cassette deck to record them on, so I want to have full OEM functionality. What should I do? Just go with my plan of getting the OEM harness which the guy I talked to about this stated " The sound quality is extremely poor" when referring to the OEM wiring or do I go aftermarket wiring?

A follow-up to this is understanding 2-channel vs. 4-channel. What is the difference and how do these types of wiring affect what I'm trying to do?

[reggieb]

You have 4 channel premium sound wiring. It uses a single wire for each radio channel output, and a single signal ground wire to the amp in your trunk. The wiring to the speakers comes from the trunk amp, not the radio. Colors are different from the radio output wiring as well. Take a look at the 1st post on this thread for a full description of your setup, including the wire colors for radio outputs, speakers, power, chassis and ground.

I did indeed read through (and printed it) but it doesn't quite match up, which is where my confusion came in

From the pics you posted, it's clear your illumination and memory wiring has been cut. You'll need to repair that to run a factory radio.

I am not interested in running a factory radio, so that isn't an issue. I have it wired to the harness on my Blaupunkt now.

Those two brown wires are "case ground" for the radio, and signal ground for the radio outputs. You will need your trunk amp plugged in, and *must* connect that case ground to get undistorted audio.

Cool, so I can just connect them in with the Brown/Black that I have connected to the ground wire out of the back of the stereo? Or do I need to actually find a ground point to connect them to?

You don't need to connect those to anything. Just plug the fader connector in.


The grey/red wire in the radio opening is NOT for speakers.

Got it, I'll cap them.

The only brown/black wire going directly to your radio should be on the power connector. There's another brown/black wire buried in the harness that goes between to the trunk amp

There was one running right in to the connector that you describe as the "Rear channel adapter" that I linked on your site. Like I said, while the adapter itself is the same physical plug, the wiring both in and out of it don't match what's on your site - that's the biggest source of pause for me.

I strongly recommend you restore your wiring to stock - don't cut it.

Man, I would have loved to not cut it, but I don't like taps, and I don't really think there is a better way to wire in an aftermarket radio. If someone made me a wiring harness, I would have gladly used it, like I have in other cars I've wired, but I couldn't find one. I cut the absolute minimum that I could, then used WAGO connectors. I still have the connectors that I cut off. I could reconnect them and lose around 1cm of length, but don't really think that's necessary. I think we'll drive this car in to the ground with an aftermarket radio in it.

Drop me a note and we can chat further. Can't really tell what's going on with your harness in that pic. I suspect your radio wiring has been cut all the way back to the fader connector.

Cool, and I did email you. Since I think I have the positives right, and I don't have any of the negatives from the wiring threads, I guess I just need to know what to connect those to. I assume that once I have the bypass in place, I will have to have a negative wired from the stereo, else the speakers won't work. Since I don't have the colors of wires described in that other threads for the negatives, what do I do? Or is it that once I have that bypass in place I just won't need anything connected to those? That just feels very wrong to me.

EDIT: From further reading, I guess I just don't connect the negatives? So why would there have been no sound? Perhaps just a dead amp that will be resolved when I get your bypass?

EDIT 2: I think that my stereo isn't going to like common ground and I should just run new speaker wire.

[bradnic]

I am trying to figure out the wiring in my car. It's a 1993 convertible (the convertible in 1993 was still an e30) and I can't quite get it.

You have 4 channel premium sound wiring. It uses a single wire for each radio channel output, and a single signal ground wire to the amp in your trunk. The wiring to the speakers comes from the trunk amp, not the radio. Colors are different from the radio output wiring as well. Take a look at the 1st post on this thread for a full description of your setup, including the wire colors for radio outputs, speakers, power, chassis and ground.

All of the POWER side stuff matches up with what is in this thread: https://www.r3vlimited.com/board/for...and-amp-bypass
I have that connected up and my new head unit powers on.

From the pics you posted, it's clear your illumination and memory wiring has been cut. You'll need to repair that to run a factory radio.

I do have an amp in the truck, and ordered the bypass only from you guys. Which I will hook up.

Already shipped out. The adapter connects the radio output wires to the amp output wires through the trunk amp connector. letting you run a radio only setup. Please note the radio you use must be compatible with 'single-ended' shared signal ground wiring.

I wanted to temporarily, while I wait for that, just check that everything is working. My speaker wires don't match up with that thread.

The factory speaker wires in a premium setup DO NOT go to the radio. There are 4 grey wires for the front channels, 4 black wires for the rear.

I am using the solid yellow and solid blue wires for the front positive, it's possible that is wrong and I should go up above wherever they're spliced, but I am using them where they come in to my 2 - 4 channel adapter, which has the same connectors as the one that you have a picture of, but different wiring (when contrasting to this: https://oemhifi.com/products/oem-2-to-4-channel-premium-sound-adapter-harness?pr_prod_strat=e5_desc&pr_rec_id=15d62ac7e& pr_rec_pid=8744351727889&pr_ref_pid=9054229954833& pr_seq=uniform)

The 2-4 channel adapter has a two black striped wires for the rear radio outputs, one yellow and one blue. The solid yellow and solid blue wires are your radio front outputs. All 4of these wires are "positive".

My negative wires are definitely all different colors than the diagram for the convertible in your OP, and at the wiring link from the other thread.

This seems to contradict what you write later on. Maybe you're talking about the grey and black speaker wires?

Here is what I have:
[/QUOTE]
That's the OEM rear channel adapter for the radio outputs. Same one you linked to on my site. The part you are holding plugs into a fader connector on your wiring harness.

All of my messing around, I never got any sound out of the system. I did try grounding the pair of brown wires that were grounded to the back of the old stereo and that didn't help either.

Those two brown wires are "case ground" for the radio, and signal ground for the radio outputs. You will need your trunk amp plugged in, and *must* connect that case ground to get undistorted audio.

Here are all of the colors that I am hooked in to for the positives:
Solid Blue (Right Front)
Solid Yellow (Left Front)
Blue/Black (Right Rear)
Yellow/Black (Left Rear)

Those are all correct.

Yellow Red (this is also left right?)
Blue/Red (Also right front?)

You don't need to connect those to anything. Just plug the fader connector in.

Grey/Red (This is in the diagram, but shows as being between the speaker and the amp, and shouldn't be wired to the stereo, but I have it running to that connector pictured)

The grey/red wire in the radio opening is NOT for speakers.

Brown/Black (Again, this is a color I understand to be running as a NEGATIVE to one of the speakers from the amp, but is wired in behind my stereo)

The only brown/black wire going directly to your radio should be on the power connector. There's another brown/black wire buried in the harness that goes between to the trunk amp

I can't get any sounds out of the speakers from what I have going on here. Do I need to splice in higher up the chain to get to the colors described in that post?

I strongly recommend you restore your wiring to stock - don't cut it.

I took pause I I thought it is possible that since I have a car that overlaps with the e36, the parts bin sharing might have changed a bit. I am also replacing a BMW stereo, but not the one that the car started life with I don't think. So that might be the source of the different wiring. Would I see different colors north of that Y split?

Drop me a note and we can chat further. Can't really tell what's going on with your harness in that pic. I suspect your radio wiring has been cut all the way back to the fader connector.

[reggieb]

...snipped all the great info...

I am trying to figure out the wiring in my car. It's a 1993 convertible (the convertible in 1993 was still an e30) and I can't quite get it.

All of the POWER side stuff matches up with what is in this thread: https://www.r3vlimited.com/board/for...and-amp-bypass

I have that connected up and my new head unit powers on.

I do have an amp in the truck, and ordered the bypass only from you guys. Which I will hook up. I wanted to temporarily, while I wait for that, just check that everything is working. My speaker wires don't match up with that thread. I am using the solid yellow and solid blue wires for the front positive, it's possible that is wrong and I should go up above wherever they're spliced, but I am using them where they come in to my 2 - 4 channel adapter, which has the same connectors as the one that you have a picture of, but different wiring (when contrasting to this: https://oemhifi.com/products/oem-2-to-4-channel-premium-sound-adapter-harness?pr_prod_strat=e5_desc&pr_rec_id=15d62ac7e& pr_rec_pid=8744351727889&pr_ref_pid=9054229954833& pr_seq=uniform)

My negative wires are definitely all different colors than the diagram for the convertible in your OP, and at the wiring link from the other thread.

Here is what I have:



All of my messing around, I never got any sound out of the system. I did try grounding the pair of brown wires that were grounded to the back of the old stereo and that didn't help either.

Here are all of the colors that I am hooked in to for the positives:
Solid Blue (Right Front)
Solid Yellow (Left Front)
Blue/Black (Right Rear)
Yellow/Black (Left Rear)

Yellow Red (this is also left right?)
Blue/Red (Also right front?)

Grey/Red (This is in the diagram, but shows as being between the speaker and the amp, and shouldn't be wired to the stereo, but I have it running to that connector pictured)
Brown/Black (Again, this is a color I understand to be running as a NEGATIVE to one of the speakers from the amp, but is wired in behind my stereo)

I can't get any sounds out of the speakers from what I have going on here. Do I need to splice in higher up the chain to get to the colors described in that post?



I took pause I I thought it is possible that since I have a car that overlaps with the e36, the parts bin sharing might have changed a bit. I am also replacing a BMW stereo, but not the one that the car started life with I don't think. So that might be the source of the different wiring. Would I see different colors north of that Y split?

[bradnic]

Yes, it's the premium sound....well, it has the trunk amp and separate tweeters so I suppose that's premium sound.

Do you know if anyone has ever made jumper wires at the amp to go between the input/outputs? If it the connectors have to be cut off in order to bypass, then I think rather than cutting them, I might buy a 4 channel amp and run RCA's from the head unit. That way I can leave the factory wiring alone. Do you happen to know what gauge power wire and size fuse is powering the factory amp? Could I use the factory power wire for a 4x75rms amp or something like that?

When you were talking about the passive crossovers being built in to the fronts, I don't think I'm following. Are you just saying to make sure I get speakers that come with a crossover?

Thanks for your help!!!

Sorry I missed this. Check out my no-cut sound system bypass harnesses at oemhifi.com

https://oemhifi.com/products/quadroboost-trunk-amp-bypass-harness

[BSAmarc]

I don't know what the trunk space looks like in a convertible, but I'm looking to mount mine to the rear of the back seat, on a board that sits behind the cardboard panel. So the install will be:

steel back seat | wooden board | cardboard panel | amp

This way I can size the board to match existing holes and bolt the amp solidly to it.

[SPOautos]

I would reach out to bradnic@oemhifi.com to see if he has anything.


30A fuse, 14 gauge wire. Since _all_ wires in and out of the factory amp go through that single that connector, you'd need to hack up the connector to get to them anyways. Better to wire up a new amp using new cabling. Since coupes and sedans have the battery in the trunk, there is an unused channel on the passenger (right) side of the car running all the way to the trunk that you can use for your cabling.


Correct. Don't just pick up 5.25" speakers expecting there to be a separate crossover behind the panels. Either buy a component sets or a separate crossover.

Thanks for the info! Okay so I can just leave the input connector alone, run a 8 gauge power wire, two sets of rca's, and auxiliary wire, down the passenger side and I guess they snake through the convertible top compartment and into the trunk. I suppose for the speaker wires I'll have to either cut the connector off or depin it.

What do you think is the best way to mount the amp in order to use the factory speaker wires? Just somehow attach it to that back wall where the original amp is? Id like to do it without drilling any holes, but not sure if that'll be possible or not.

[BSAmarc]

Do you know if anyone has ever made jumper wires at the amp to go between the input/outputs? If it the connectors have to be cut off in order to bypass, then I think rather than cutting them, I might buy a 4 channel amp and run RCA's from the head unit. That way I can leave the factory wiring alone.

I would reach out to bradnic@oemhifi.com to see if he has anything.

Do you happen to know what gauge power wire and size fuse is powering the factory amp? Could I use the factory power wire for a 4x75rms amp or something like that?

30A fuse, 14 gauge wire. Since _all_ wires in and out of the factory amp go through that single that connector, you'd need to hack up the connector to get to them anyways. Better to wire up a new amp using new cabling. Since coupes and sedans have the battery in the trunk, there is an unused channel on the passenger (right) side of the car running all the way to the trunk that you can use for your cabling.

When you were talking about the passive crossovers being built in to the fronts, I don't think I'm following. Are you just saying to make sure I get speakers that come with a crossover?

Correct. Don't just pick up 5.25" speakers expecting there to be a separate crossover behind the panels. Either buy a component sets or a separate crossover.

[SPOautos]

Do you happen to know if you have the "premium sound" with tweeters in the doors? This is the easiest indication of whether the car came with the amp or not. Depending on what power output the Kenwood stereo has, it's likely that bypassing the factory amp is your best bet. The process is fairly simple as long as you're comfortable cutting into the stock harness. It is a bit destructive and, depending on how cleanly you do it, can or can't be easily put back to stock at a later time.

At the amp, you just need to identify input wires (one per channel, they share a ground) and tie them to their corresponding output wire (plus add ground wires since stock output uses two wires). The speaker wire in the later models include +ve and -ve and are decent enough for a basic system. If you'd rather replace the amp altogether, that's likely to be even more work as you're not going to find something that uses the factory plug and you'll have to work out how to get signal to it, along with power.

On my build I just added RCA down the center console, out to the trunk, and am leaving the speaker signal disconnected at the head unit. I'm replacing the factory amp in my car with an aftermarket and reusing the existing twisted pair speaker wires for simplicity.

Lastly, if you find that the speakers need replacing (and you have tweeters) keep in mind that the passive crossovers were built in to the 5.25" speakers so you'll want to take that into consideration when purchasing replacements.

Yes, it's the premium sound....well, it has the trunk amp and separate tweeters so I suppose that's premium sound.

Do you know if anyone has ever made jumper wires at the amp to go between the input/outputs? If it the connectors have to be cut off in order to bypass, then I think rather than cutting them, I might buy a 4 channel amp and run RCA's from the head unit. That way I can leave the factory wiring alone. Do you happen to know what gauge power wire and size fuse is powering the factory amp? Could I use the factory power wire for a 4x75rms amp or something like that?

When you were talking about the passive crossovers being built in to the fronts, I don't think I'm following. Are you just saying to make sure I get speakers that come with a crossover?

Thanks for your help!!!

[BSAmarc]

Do you happen to know if you have the "premium sound" with tweeters in the doors? This is the easiest indication of whether the car came with the amp or not. Depending on what power output the Kenwood stereo has, it's likely that bypassing the factory amp is your best bet. The process is fairly simple as long as you're comfortable cutting into the stock harness. It is a bit destructive and, depending on how cleanly you do it, can or can't be easily put back to stock at a later time.

At the amp, you just need to identify input wires (one per channel, they share a ground) and tie them to their corresponding output wire (plus add ground wires since stock output uses two wires). The speaker wire in the later models include +ve and -ve and are decent enough for a basic system. If you'd rather replace the amp altogether, that's likely to be even more work as you're not going to find something that uses the factory plug and you'll have to work out how to get signal to it, along with power.

On my build I just added RCA down the center console, out to the trunk, and am leaving the speaker signal disconnected at the head unit. I'm replacing the factory amp in my car with an aftermarket and reusing the existing twisted pair speaker wires for simplicity.

Lastly, if you find that the speakers need replacing (and you have tweeters) keep in mind that the passive crossovers were built in to the 5.25" speakers so you'll want to take that into consideration when purchasing replacements.

[SPOautos]

Brand new here and to the e30! I've bought my wife a 91 convertible and recently started having the front speakers intermittently cut out. I didn't realize there was an amp and all this wiring complexity, I just figured the stereo was going bad. I purchased a Kenwood Excelon x705 thinking it would just be a normal install and thought I might add a small under seat powered sub. My wife doesn't care about having a 'system' she just wants to hear her music with the top down on the interstate.

Are the real old threads about bypassing the amp still the best way? Id like to preserve all the factory wiring so that it could easily be put back to stock at some point. With there being so many cheap amps now a days, I wouldn't mind just replacing the amp with something like a small 4x50rms amp to power all the 5.25" using all the factory wiring if that's possible....but would the factory amps power be wire sufficient for that?

Anyone have any suggestions or thoughts? I'm a bit overwhelmed at what direction to take, I wasn't planning on a huge project lol

[mbuse]

so it turns out that in Europe, some late model E30s including the tourings used the 17 pin connector found in early E36 cars. That single connector combines all the radio wiring including 4 radio output channels, power and ground. Tourings all came with 17 pin harnesses, part numbers 61-12-1-394-213 (sound system) and 61-12-1-394-212 (radio only). There were also part numbers for coupe/sedan/M3, 61-12-1-394-211 (sound system) and 61-12-1-394-210 (radio only). Convertibles had 17 pin harnesses as well, 61-12-1-394-215 (sound system) and 61-12-1-394-214 (radio only).



There are some very cool OEM BMW radios with this connector. They won't sit flush on your HVAC panel without modification, but you can get a 3d printed bracket for that thanks to D.Martijn, thread here. I will have these on my website shortly for $15 (basically the cost of printing with a small margin). I will also have an HVAC switch blank adapter for the Cantaloupe Radio microphone.

You can also get 2 or 4 channel harness adapters from BMW like 65-12-8-350-192 to add the connector to your car if needed, or make it yourself once you source the right connectors (square connector bot hard, rest not easy, especially the proprietary fader connector). There were multiple versions of these adapters for 2 or 4 channel wiring, radio only or sound system.


Here's an example that is THE OPPOSITE of what you would need. One of my customers with 17 pin Touring wiring put this together with my help so he could run a CM5908 and Cantaloupe Radio BT. BMW sold a similar adapter as 65-12-8-350-189:

I've been meaning to post on this thread since Brad helped me install the CM5908 I purchased from him last fall (sorry this has taken so long Brad!). I'm the customer with the touring Brad is referring to and the picture showing the wiring is what I made to help me double check I was connecting the correct wires.

The adapter I purchased (which Brad had shared with me) is found on Amazon: https://a.co/d/gBKPKy4. You just need to cut off the smaller black and brown connectors and wire them to the connectors that plug into the radio.

The numbers written on the page correspond to the pin numbers on the 17-pin connector. I then used the pin diagram Brad shared in the post above to line up with the wires purchased from OEM Hifi (https://oemhifi.com/products/cantalo...stallation-kit) to make an adapter from the CM5908 to the wiring in my touring (1993 316i).

Attached are a few more pictures of the connector in my car if that helps anyone. Happy to answer any other questions for other touring owners out there!

Huge thanks again to Brad for all the install help! His refurbished radios and harnesses are top notch!

[bradnic]

Do you have a list of part numbers for the amp and door crossover harnesses? I've found the radio harness but haven't seen any others.

You’ll have the 718 or 719 harness depending on the car. Check the 1st post..

My recent purchase (1991 325i w/BMW sound) came with a full system in boxes, including head unit, Alpine 5-channel amp (going to run RCA from HU to new amp), sub box, and front and rear speakers. I think one of the sets of speakers are the same Focal ones you've got listed. From your pics it looks like you spliced into the door speaker wires for the crossover inputs, but I figured I would ask.

you need to decide if you want to restore the factory wiring first - I definitely would but it’s your call. Feel free to drop me a note to discuss further bradnic@oemhifi.com

[BSAmarc]

For those of you considering speaker or amplifier upgrades, harness adapters can be used to protect the factory wiring. Speaker upgrade options vary based on the body type, but in general:

1. speaker sensitivity is important to balance sound between front and rear. without that balance you'll need to move the fader off of center
2. component speakers like the Focal 130AS are great replacement for the kick panel speakers and door tweeters. I wouldn't personally modify the tweeter pods, instead pick up another set or get some 3d printed versions
3. for convertibles, the top priority speaker wise is to replace the standard rears with coaxials. Speakers like the Focal ACX130 are a great choice here.
4. for those with premium wiring, you can add a no-cut amp bypass harness now which will let you keep or swap out the factory trunk amp, add a monoblock amp and passive sub, a 5 channel amp or a 4 channel amp and powered sub. cars with front batteries will need to wire power to the trunk to run a sub.

Here's an example of a front speaker upgrade using the Focal 130AS component speakers. There are harness adapters for the new crossovers and door tweeters, as well as a kick panel spacer to keep the new speaker surround from hitting the trim.

Do you have a list of part numbers for the amp and door crossover harnesses? I've found the radio harness but haven't seen any others.

My recent purchase (1991 325i w/BMW sound) came with a full system in boxes, including head unit, Alpine 5-channel amp (going to run RCA from HU to new amp), sub box, and front and rear speakers. I think one of the sets of speakers are the same Focal ones you've got listed. From your pics it looks like you spliced into the door speaker wires for the crossover inputs, but I figured I would ask.

[bradnic]

so it turns out that in Europe, some late model E30s including the tourings used the 17 pin connector found in early E36 cars. That single connector combines all the radio wiring including 4 radio output channels, power and ground. Tourings all came with 17 pin harnesses, part numbers 61-12-1-394-213 (sound system) and 61-12-1-394-212 (radio only). There were also part numbers for coupe/sedan/M3, 61-12-1-394-211 (sound system) and 61-12-1-394-210 (radio only). Convertibles had 17 pin harnesses as well, 61-12-1-394-215 (sound system) and 61-12-1-394-214 (radio only).



There are some very cool OEM BMW radios with this connector. They won't sit flush on your HVAC panel without modification, but you can get a 3d printed bracket for that thanks to D.Martijn, thread here. I will have these on my website shortly for $15 (basically the cost of printing with a small margin). I will also have an HVAC switch blank adapter for the Cantaloupe Radio microphone.

You can also get 2 or 4 channel harness adapters from BMW like 65-12-8-350-192 to add the connector to your car if needed, or make it yourself once you source the right connectors (square connector bot hard, rest not easy, especially the proprietary fader connector). There were multiple versions of these adapters for 2 or 4 channel wiring, radio only or sound system.


Here's an example that is THE OPPOSITE of what you would need. One of my customers with 17 pin Touring wiring put this together with my help so he could run a CM5908 and Cantaloupe Radio BT. BMW sold a similar adapter as 65-12-8-350-189: