Easy way to install an aftermarket radio into your factory amplified system

[12v Electronics]

70-8590 is the one you want. You will need an antenna adaptor also. I have both of them in stock if you need them.

[EKMurakami]

Here's a picture of the Pioneer radio I installed into my Volkswagen Corrado using the Metra 70-1785 amp integration harness into a common ground factory amplified stereo system. I installed it EXACTLY as I have in the diagram and it worked perfect.


And this is what the Metra 70-1785 harness I used looked like.



This is what you need to use on certain year VW's to change out your factory radio for an aftermarket one and still keep your common ground factory amp and speakers with out having to rewire anything or bypass the amp. I know it worked because I used the harness and I had a working radio and working factory amp.

This harness below is the one I would have had to use to hook up an aftermarket radio if I didn't have the common ground factory amplified stereo system.



I had installers at a Best Buy swearing up and down to me that there was absolutely no way to keep the factory amp and not have to rewire all the speakers when hooking up an aftermarket radio to a common ground amplified system and they wanted to charge me $130 for just the re-wiring and after a little research, $15 later for the Metra harness and a few minutes installing I had a great sounding stereo system with nothing changed other than just the head unit.




It does work..I've done it before with no problems on other cars and even other people on here have said that they had multiple BMW's that had the older system and they did the aftermarket head unit swap on each one with doing it that exact same way that I have in the lower diagram and had no problem at all. I guess they are all wrong too because they did it and it worked, but because you don't think it will work, they are wrong.

I have it in my E34 right now and guess what....IT WORKS!! Don't tell me it won't because IT IS WORKING!

How many factory amplified systems have you changed out a factory radio for an aftermarket one without bypassing the amp and rewiring the speakers?

I know that I've only done 3, but they went together with absolutely no problems at all and exactly how they are diagrammed above. Instead of just telling me that it won't work, try it like I have it diagrammed and see for yourself. You can try to tell me over and over again what your opinion is about this, but I'm the one who had successfully done it 3 times with absolutely no problem at all.

Results speak more than words.

Find someone with a BMW which uses the 17 pin harness and has the factory amplified system somewhere near Rochester, Michigan who wants to swap their factory radio for an aftermarket one without bypassing the factory amp and rewire the speakers and I'll be more than happy to prove you wrong.

I have the Metra harness, just find someone and I'll be more than happy to show them how.

We have tried the above procedure and it does work! Our wiring harness was one of those pre-17 pin plug days. Thanks!!!

[LVZX14]

so you can't run the stock amp with an aftermarket amp? I probably misread something so if I did my apologies

[attack eagle]

Blah blah blah...

Here is the Skinny

OP you are wrong.
period.

CG to aftermarket head, wire without using negative leads, done that gives you 7x4 watts divided by 8-10 speaker.

CG to aftermarket head, run 4 new negatives to the amp, by pass amp chip and conenct direct to the xover board that gives you 15-17wx4 divided by 10 speakers
(ie more than 2x the power of the factory amp)

CG to aftermarket head with 4 channel amp: rcas to amp, amp to xover board as above. _____w x4 to 10 channels.




Tom, the 89-90 CG head do NOT use the metra adapter. they are like an 85 head for argument's sake.


end thread...

THIS



is a damn stupid idea...

take a good balanced connection and turn it into a low level unbalanced rca with no shielding at 1/2 or 1/4 of the needed input. it is NOT needed or desireable.

read up on balanced vs unbalanced, and what twisted pair is (hint, it should only ever be used with balanced connections, never low level unbalanced rca), and you will see there is NO shielding against noise... they are just plain speaker wires, aka the factory amp is a HIGH LEVEL INPUT AMP.

As for why metra sells them... well, YOU bought one iddn;t you? you were on here esposing them even though they are proven to be a bad idea in theory and in practice. You believe RCA is better than 'wires', like most other uneducated audio users. People buy shamwows, extendz, CAIs, and all other kinds of 'doesn;t work' products. If a fool will buy it for 15x cost, they'll make it.

[tberardi]

I was fooled as well by all the hype with the Metra dapters. I thought, I could use the factory amp and builtin crossovers for the 14 speakers with a new radio as this would be much ceheaper than retrofitting with BMW NAV system.

So I purchased an aftermarket 7" DVD flip screen with all the features including GPS and tried to install it in my 95 740i today with no success.
I currently have the C23 head unit with DSP and factory amp & CD changer.

Prior to undertaking the exchange, I studied the Bentley manual schematics and those on E38.org first. People are not kidding when they say the factory system is highly integrated and tough to modify with aftermarket units.

Although the new radio fit well in the factory socket, its a tight sqeeze as there is not much room in there for all the wires and RCA jacks that came with the unit.

Before I plugged the Metra 8591 on the factory harness plug, I examined all the existing pins and compared to the schematics. Everything was fine until it came to where to connect the 4 RCA preouts.

There are only 2 wires on pin 1 & 2 for the front L&R with the associated ground lead missing which goes to the amp. However, I found the brown-orange wires looped back into the harness just behind plug and they led back along the harness to under the center console. I did not chase to see where they go.

Further, there were no leads in the factory harness for the Rear R&L nor for the rear deck woofers.

I was (and still am) stumped at this point and tried a number of experiments all to no avail including using the coax output thru the CD changer's digital output into the amp.

How does the factory unit control fading if there is no rear leads from the head unit to the amp. Does it do it thru the I-bus.

When the head unit is removed from the system, does the amp shut down and therefore, it doesn't matter what you do, you can never use an aftermarket radio with the factory system due to the bus connections, fm amplifier and antenna amplifier connections.

I thought about running 8 new wires to the trunk and splice into the speaker wires at the amp output harness , but there are 14 speakers to hook up. Maybe I should buy some two & three way cross overs and use them to create 4 seperate channels to connect into all these speakers.

Maybe its better to buy a new amp and new speakers - getting complicated and pricey now?

I am looking for comments and advice on my next steps.

The list provided by the Eagle is a little technical but I will try to decode it as it sounds good.

Thank you to all who forward comments and advice.

[12v Electronics]

MODS, please close and bury this thread before it confuses anyone else.

[attack eagle]

I was fooled as well by all the hype with the Metra dapters. I thought, I could use the factory amp and builtin crossovers for the 14 speakers with a new radio as this would be much ceheaper than retrofitting with BMW NAV system.


How does the factory unit control fading if there is no rear leads from the head unit to the amp. Does it do it thru the I-bus. YES

When the head unit is removed from the system, does the amp shut down and therefore, it doesn't matter what you do, you can never use an aftermarket radio with the factory system due to the bus connections, fm amplifier and antenna amplifier connections.
ALMOST, need an Ibus ?interrogator? ?here I am? to tell the amp the factory head is still installed and it should stay on... you'll have to build and figure that one out yourself...

Maybe its better to buy a new amp and new speakers - getting complicated and pricey now?
and keep the OEM head? sure.



Thank you to all who forward comments and advice.

ok, you have an e38 right? TOTALLY different set up... search for e38 in here , and yes the amp runs everything via IBUS. I do not recall 100% if that is one of the ones that relies on Ibus to keep the amp turned on or not either, but a search here will answer that question. I am pretty sure it is.

e38, mid 90s car, digital architecture etc.
e34 designed in the 80s so is analog based.
COMPLETELY different cars, sorry.

The OP's bad info and poor advice was confusing even to me, and I'm the defacto expert on e34 factory audio systems...

this thread needs to be terminated... post haste and with extreme prejudice.

[tberardi]

Thank you eagle for the comments.
Its getting fun now.

[Yahweh]

what about this?

http://www.crutchfield.com/p_127OEM2...2.html?tp=3486

[Halston Pitman]

You want the 70-8590. You wire it to the included wire harness(comes with your aftermarket radio) and do that properly and you now have a plug and play install! Grab your antenna adapter. Plug and play that and you are jamming out!

[89BMW735il]

i followed the diagram "itsnevo" provided. works great on my 89 735il.

bashing ideas that work?? i dont get it..

MODS, please close and bury this thread before it confuses anyone else.

the information you bashed works.. for the earlier cars that the connectors on the back of the radio were small and many. i used his diagram and wired up a stereo to my car and it works.

maybe you just bashed his idea cause it cost nothing and you want customers...

[aurule]

I know this is a really old thread, but I wanted to let itsnevo know that, thanks to his advice, I just used the Metra harness on my '98 328 and it worked like a charm. Five wires to mate plus the RCA plugs. I haven't installed a radio since my first car some time in the early 70's, but it took about half an hour and the system sounds great.

[maitide95]

I used the 70-8590 metra adapter in my 1995 525i with antenna adapter and it works beautifully with my Alpine 7525 aftermarket. It took 20 minutes. Its an old car and I don't care how many watts are going to what speaker; it sounds better than the stock Alpine ever did and I saved the $220.00 the local shop wanted. Although this thread is old to this forum it's new to me and I must say with all the bickering amongst certain contributers it almost desuaded me from trying. People come here for help and first hand knowledge, so they may accomplish something on their own and save a little money. If I had never read all of this I would have just installed the radio with the adapters Best Buy sold me and I never would have known it may not have worked; BECAUSE IT DID.

[duffbeerracing]

thanks for the expose

[Tismael711]

I need help! Someone broke into my 1991 525i with an aftermarket Alphine radio and cut and mangled all the damn wires. What i have left is a 17 pin wire and an antennae wire. What do i need to re-install either a factory radio or an aftermarket radio? Good, sound advice and pictures would help!!

[12v Electronics]

I need help! Someone broke into my 1991 525i with an aftermarket Alphine radio and cut and mangled all the damn wires. What i have left is a 17 pin wire and an antennae wire. What do i need to re-install either a factory radio or an aftermarket radio? Good, sound advice and pictures would help!!

If you are going aftermarket, just tie the new wires into the cut ones. If you want stock there is a connector available. Let me know if you decide to go that route and I can help you there.

[AspenSilverE39]

ARGH x2!!

Search and learn before you post nonsense like this. It is not correct for all cars. and definitely not correct for getting more power from the stock audio system.

+1

You do not need to use "AMP integration harness" with most bmw factory amps. I've had E32, E34, E36, E39, and E46, and in all of them the Pioneer Premier DEH-P710BT played very well with factory AMP using standard aftermarket wiring harness.

[kevinknutson]

I too used this exact harness (the Metra 70-8591) you're talking about in my '91 535i when changing out my factory head unit for a JVC RD820-BT and factory 5.25'' speakers for 5.25 JBL GTO's. I still kept my factory amp. It worked great. Y'all need to read what the guy is saying. Not what you Think he's saying. It works, it's proven, give it up.

[106pequot]

Here's a picture of the Pioneer radio I installed into my Volkswagen Corrado using the Metra 70-1785 amp integration harness into a common ground factory amplified stereo system. I installed it EXACTLY as I have in the diagram and it worked perfect.


And this is what the Metra 70-1785 harness I used looked like.



This is what you need to use on certain year VW's to change out your factory radio for an aftermarket one and still keep your common ground factory amp and speakers with out having to rewire anything or bypass the amp. I know it worked because I used the harness and I had a working radio and working factory amp.

This harness below is the one I would have had to use to hook up an aftermarket radio if I didn't have the common ground factory amplified stereo system.



I had installers at a Best Buy swearing up and down to me that there was absolutely no way to keep the factory amp and not have to rewire all the speakers when hooking up an aftermarket radio to a common ground amplified system and they wanted to charge me $130 for just the re-wiring and after a little research, $15 later for the Metra harness and a few minutes installing I had a great sounding stereo system with nothing changed other than just the head unit.




It does work..I've done it before with no problems on other cars and even other people on here have said that they had multiple BMW's that had the older system and they did the aftermarket head unit swap on each one with doing it that exact same way that I have in the lower diagram and had no problem at all. I guess they are all wrong too because they did it and it worked, but because you don't think it will work, they are wrong.

I have it in my E34 right now and guess what....IT WORKS!! Don't tell me it won't because IT IS WORKING!

How many factory amplified systems have you changed out a factory radio for an aftermarket one without bypassing the amp and rewiring the speakers?

I know that I've only done 3, but they went together with absolutely no problems at all and exactly how they are diagrammed above. Instead of just telling me that it won't work, try it like I have it diagrammed and see for yourself. You can try to tell me over and over again what your opinion is about this, but I'm the one who had successfully done it 3 times with absolutely no problem at all.

Results speak more than words.

Find someone with a BMW which uses the 17 pin harness and has the factory amplified system somewhere near Rochester, Michigan who wants to swap their factory radio for an aftermarket one without bypassing the factory amp and rewire the speakers and I'll be more than happy to prove you wrong.

I have the Metra harness, just find someone and I'll be more than happy to show them how.

I tried to install my aftermarket radio according to the diagram with multipule small connectors using only the + speaker wires. It does not work........... Still trying to figure a way to do this without running seperate grounds to eevery speaker. Does anyone know for sure aguarenteed way of doing this.

The RCA cables on that top harness plug picture plug into the rear of the aftermarket radio (preamps), they do not go to RCA cables that run all the way to an aftermarket amplifier. It is plugging the amp integration harness RCA's into the head unit preamps that complete the signal for sound to travel to the factory amp. If you tried to run RCA's from the Metra harness back to an aftermarket amp, the radio would have no way to send any sound signals to the amp, so it would be just like connecting an extension cord to itself, you are cutting out the part of the system that creates the signal and no power will be transferred. Just think of it this way...on the factory harness you have the speaker wires going from the amp to the headunit. When you change the radio to aftermarket and use the Metra harness, it changes those wires into RCA's. If you tried to send the RCA's back to the amp, then you will now have no speakers hooked up to the head unit because you just sent those speaker wires back away from the radio. The whole reason this adapter was made was to simply swap out your factory radio and install an aftermarket radio without having to bypass the factory amp. I know for a fact that this harness is made for keeping your OEM amp and just changing your head unit to an aftermarket one. I've done 2 cars both with a common ground factory amplified sound system using this type of harness and in each case I changed out the factory radio and kept the OEM amp and speakers without rewiring anything.

The harness below that one is for a non amplified system where the speakers are powered directly off the head unit itself and not an OEM amplifier. By using that harness on an OEM amplified system, you would have to bypass the amp and run all new wires from the head unit to all the speakers. That again is why the amp integration harness was made.

As far as having to start from scratch on your 86 535i with the common ground system, if you had a similar radio that I had in my 90 525i where there are several smaller connectors that connect to the rear of the radio, you didn't have to do all that. There are ways of connecting an aftermarket radio to a common ground amplified speaker system without having to "start from scratch" and that is why I posted this information up. The sad thing is if you have a similar system as I do, you didn't have to buy any additional harnesses, bypass the factory amp or run any new wires at all. All you need is the aftermarket radio harness and some connectors.

And just to clarify, I do have the common ground factory amplified system found in older E34's in my car with a JVC aftermarket radio in it now working awesome and I am using the OEM amp and speakers without running new wires to any of the speakers and it took me about 7 minutes to install the JVC radio into my car.

I've installed aftermarket radios into 3 cars now that had an OEM common ground amplified system without having to bypass any amp or rewire any speakers.


Here is a diagram on how you would use the Metra amp integration harness to swap out a factory radio for an aftermarket one into a BMW with the factory 17 pin wire harness without having to bypass the factory amp and rewire any speakers. You need to connect the RCA cables to the rear and front preamp outputs on the rear of the radio because this is what makes the factory amp get the signal to produce sound. Otherwise you will only be running a remote turn on wire to the amp and that's it. These RCA's are NOT intended for an aftermarket amplifier with a factory head unit.



Here is how you replace a factory radio for an aftermarket radio with the older BMW radio harness with many smaller connectors into a common ground amplified system without having to bypass the factory amp and rewire all the speakers. I know for a fact that this works because I'm driving a 1990 E34 with a JVC HD radio in it right now and I didn't bypass any amp or replace any speaker wires.



These are only for BMW factory amplified stereo systems that are the same as the two available in the E34's. The top diagram was used on the factory amplified stereo systems found on the 92 to 95 E34's and the bottom is what was used on the common ground factory amplified systems found on the 89 to 91 E34's.

The bottom diagram was a diagram that I found on the internet. I took a meter to the two 12 volt wires to see which one was the 12v switched and which one was a continuous 12v source. Make sure you connect the two brown wires that are twisted together and have a loop connector that was mounted to the rear of the factory radio onto the aftermarket radio. Unless there is some new adapter out there that I am unaware of, you will have to cut the wires going to the 12v switched, 12v constant, ground, antenna/amp turn on and speaker wires from the connectors going to the rear of the factory radio and connect them to the corresponding wires on your aftermarket head unit harness. Seeing as this is a common ground system, on the diagram where is shows #6 through #13, there will only be 4 wires that connect to the radio and those are all your + speaker wires. On your aftermarket radio harness there will be both the + and - wires, but all you need to connect is the + wires. Tape off the - speaker wires on your aftermarket wire harness, you won't use them at all.

If anyone has a BMW with the 17 pin connector on the rear of their factory radio and they want to upgrade just their head unit while keeping their factory amp and speakers, I am selling the 17 pin Metra amp integration harness I have for $15, and I would be more than happy to help install the new head unit totally free to show the buyer how easy it is to use and show how you don't have to bypass the amp and run all new wires. I bought the Metra harness not knowing that I didn't have the newer 17 pin factory harness.

For anyone who has the older style radio wiring which has several smaller connectors that plug into the rear of the factory radio like mine was with the common ground amplified system and they want to swap out their factory radio for an aftermarket one while keeping the OEM amp and speakers, I would be more than happy to show them how easy it is to install. It took me about 7 minutes to install my JVC HD radio into my OEM common ground amplified system.

If anyone near the Rochester, Michigan area would like to see how easy it is, let me know. This doesn't have to be a huge project to tackle. This is way easier, quicker and cheaper than some people on here make it out to be.

If anyone still doubts that the Metra amp integration harness is designed to allow you to keep your factory amp and speaker wiring in a factory amplified common ground system while letting you just change out your factory head unit for an aftermarket one, I'll be using another Metra amp integration harness in another common ground factory amplified car sometime soon and I'll take pictures of the step by step process and post them up here.

I just tried to install my aftermarket radio according to the=is diagram, leaving off the -speaker wires and it does not work, am I missing something. I wired it exactly as showed and explained.

[MightyWhitey]

Didn't work in 95 540i either

[linkeds2]

put on record that i have a '94 325i with the 8 speaker factory amplified system.

i cut off my oem harness and spliced in my pioneer harness.

i had to wire the white/whitenblack wire to my amp remote on my pioneer.

everything works fine albeit the speakers in the back suck for bass

didnt need any amp integration harness or needed to use rca preouts on the radio

[12v Electronics]

put on record that i have a '94 325i with the 8 speaker factory amplified system.

i cut off my oem harness and spliced in my pioneer harness.

i had to wire the white/whitenblack wire to my amp remote on my pioneer.

everything works fine albeit the speakers in the back suck for bass

didnt need any amp integration harness or needed to use rca preouts on the radio

Or you could have used the adaptor I recommended and not had to cut up your cars wiring harness. Either way works.

[linkeds2]

i'm the pretty impatient type lol and waiting 2 weeks and paying 20$ for the adapter didnt sit well

if i decided to go back oem (which will probably never happen, even if i sell the car) i'll end up rewiring the old connector back in.

[Max6000]

Hi everyone. I have a problem, in my car(e38 740 1995) audio with DSP (12 speakers).
Will Metra 70-8591 be working?
I took a picture and I can see the wires not the same position that it should be.
Please help me what I can do.

[Max6000]

You mean "this devise" - Metra 70-8591?