1990 928GT OEM stero install.....please help with wiring mess

[sbarc]

I'm a long time lurker and I've gleaned much helpful advice from you guys as I find my way around my car.
I've got a very tidy, low mileage 1990 928GT that I want to install a factory radio/CD into. I understand the factory stereos are not exactly the best units, but I need the car to have the stock stereo to qualify for the ultra cheap collector car insurance.
I've purchased the correct unit but I'm now faced with the task of installing it.
A few questions.

1) There doesn't seem to be a box for my stereo to slide into.....was there origianlly a Porsche box that the stereo slid into?



2) On the back of the OEM Stereo there seems to be just 3 places for wires to plug into.....one for the antenna and one for the power plug and one for everything else (I'll call this the "Magical" Receptacle).


3) The car had a aftermarket stereo fitted and any orignal wiring was hacked where necessary to fit the aftermarket stereo.
A is a brown wire with what appears to be a factory female connector on the end.
B unknown red wire no connector on the end
C unknown red wire no connector on the end
D Factory plug that will plug into the back of the OEM stereo
E this wire was connected to a wire on the aftermarket stereo that was labeled "ANT REM MAX 0.1A
F this wire was connected toa wire on the aftermarket stereo that was labeled "AMP REM MAX 0.3A
G small black wire that runs along with the antenna wire
H Antenna wire
I Orange wire of unknown purpose
J+K speaker wires.

Will all these wires go into the "Magical" Receptacle as seen in photo #2?
My plan is to pick up a factory plug that will plug directly into the "Magical" Receptacle on the back of the OEM stereo. I hope to get this plug from a wiring harness and simply connect the wires back up to the wires hanging in my car?
Any help you can offer would be greatly appreciated.
Steve B

[Danglerb]

I'll just scratch at this a bit until one of the experts like Alan shows up.

Pretty sure it should have a metal sleeve for the radio, but its a standard type of part and should not be hard to find.

Good chance the old owner butchered more of the wiring than just behind the radio. Porsche and many other factory radios of that era used a separate amp to drive the speakers, while most newer aftermarket radios can drive speakers directly. J&K look to me like speaker wires, so the factory amp (if your model came with one) may be bypassed or removed.

Is it possible to put the factory radio in, with nothing or just the lights hooked up, get the insurance, then put in a decent radio for day to day use, and keep the factory unit in case its needed for insurance later on? Once you have the new metal sleeve installed and proper wiring swapping them could be a matter of minutes.

You will need to buy the adapter harness with plugs to fit the factory radio, but those may also be generic or common to the brand and not difficult to find.

What I would look at doing is to restore the factory wiring and connectors and use adapter wiring harnesses for any changes.

Good luck, and wait to see what the experts have to say.

[sbarc]

Originally Posted by Danglerb

Pretty sure it should have a metal sleeve for the radio, but its a standard type of part and should not be hard to find.

Good point.....I never even thought that the sleeve the radio slides into is common to more models....but that would make sense because the stereo is used in different models.

Good chance the old owner butchered more of the wiring than just behind the radio. Porsche and many other factory radios of that era used a separate amp to drive the speakers, while most newer aftermarket radios can drive speakers directly. J&K look to me like speaker wires, so the factory amp (if your model came with one) may be bypassed or removed.

I did check and the factory amp is in the car...whether is it hooked up remains to be seen. The aftermarket unit was a Sony and it lacked all bass.......which might be an indication the factory AMP wasn't hooked up?

Is it possible to put the factory radio in, with nothing or just the lights hooked up, get the insurance, then put in a decent radio for day to day use, and keep the factory unit in case its needed for insurance later on? Once you have the new metal sleeve installed and proper wiring swapping them could be a matter of minutes.

You will need to buy the adapter harness with plugs to fit the factory radio, but those may also be generic or common to the brand and not difficult to find.

What I would look at doing is to restore the factory wiring and connectors and use adapter wiring harnesses for any changes.

Good luck, and wait to see what the experts have to say.

You raise some very good ideas. Right now I have the factory unit sitting in the hole......and that is good enough for the photos for the insurance application. I do like your idea of swapping the factory unit out for a better until by using a proper factory plug for the wiring harness. That will be my next job.....sourcing out a proper plug for the factory unit and then rigging an aftermarket unit to plug into the factory wiring. I REALLY don't want to take my car to a local stereo shop if I can avoid it, so I'm hoping to sort all this out on my own with help from here.

Thanks for the input and ideas.....MUCH appreciated.

[Alan in AZ]

Originally Posted by sbarc

1) There doesn't seem to be a box for my stereo to slide into.....was there origianlly a Porsche box that the stereo slid into?

No - but there is a perforated sleve that goes just at the front few inches - the DIN units snap into this for retention. You should be able to find one used - they are common across many Porsche models and aren't specific to Porsche either...

Originally Posted by sbarc

2) On the back of the OEM Stereo there seems to be just 3 places for wires to plug into.....one for the antenna and one for the power plug and one for everything else (I'll call this the "Magical" Receptacle).

The magic receptacle is a DIN socket - you can find plugs & pre built wires in various lengths - check on ebay - they have various numbers of connectors so be careful. This goes from the head unit to the amp and has 4 channels (LF/RF/LR/RR) and the on/off control for the amp. You will need to get a connector for the power - one with wire tails is probably easiest to deal with. It is likely the power connector has ground/battery power/switched power/antenna power/variable illumination - find out which is which - get an online manual for the unit.

In order to work on the stereo install - take off the side panels of the console (esp the passenger side) - they just unscrew - don't even think about doing it just from the front...

Originally Posted by sbarc

3) The car had a aftermarket stereo fitted and any orignal wiring was hacked where necessary to fit the aftermarket stereo.
A is a brown wire with what appears to be a factory female connector on the end.

This is probably the alarm connection that goes to the frame that is missing - alarm is triggered if head unit is removed

Originally Posted by sbarc

B unknown red wire no connector on the end
C unknown red wire no connector on the end

These are probably switched and unswitched wires - does one of these have a thin white line - if so thats the switched one.

Originally Posted by sbarc

D Factory plug that will plug into the back of the OEM stereo

you probably need another with longer wires unless you can remove and add connactors to this one - and know what connectors go where...?

Originally Posted by sbarc

E this wire was connected to a wire on the aftermarket stereo that was labeled "ANT REM MAX 0.1A

This is the power feed for a power antenna or antenna amp - do you have a powered antenna?

Originally Posted by sbarc

F this wire was connected toa wire on the aftermarket stereo that was labeled "AMP REM MAX 0.3A

This is the remote turn on for an amp (on the stock radio this should have been in the DIN plug).

Originally Posted by sbarc

G small black wire that runs along with the antenna wire

This should also be connected to "E" (or F) it would seem - this is the remote antenna amplifier.

Originally Posted by sbarc

H Antenna wire

Obvious

Originally Posted by sbarc

I Orange wire of unknown purpose

probably variable illumination

Originally Posted by sbarc

J+K speaker wires.

These are preamp wires not speaker wires. They may possibly have been used as speaker wires -they probably go to your existing amp or an aftermarket amp - check. If there is a DIn plug on the amp do these connect to that? In any case you will need a new DIN connector betwen amp & head unit - trash these. At the amp are the speakers still plugged in - are the speaker wires cut & spliced after the amp or unmolested?

Originally Posted by sbarc

Will all these wires go into the "Magical" Receptacle as seen in photo #2?
My plan is to pick up a factory plug that will plug directly into the "Magical" Receptacle on the back of the OEM stereo. I hope to get this plug from a wiring harness and simply connect the wires back up to the wires hanging in my car?

No just buy a new generic one - on any factory loom you will find - I will guarantee one end is already snipped off just like yours - so it doesn't help you one bit... e.g. http://www.opengroup.com/daddario/FOOA/PW-DIN8-05.shtml (you do not want "mini-DIN" those are computer cables only) - here are the connectors on ebay: http://cgi.ebay.com/Commodore-64-128-8-Pin-DIN-Video-Plug_W0QQitemZ160243617535QQihZ006QQcategoryZ3543Q QrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp163 8Q2em118Q2el1247
Be warned though - these are very hard to solder onto a cable...

Alan

[Danglerb]

Lacking all bass... yipes .... on mine that meant all the front speakers were bad. The paper of the cone was intact, but nothing was left of the surround, the foam or rubber ring that attaches the cone to the metal speaker basket. No surround means no seal, and that means no bass. It is possible to have the surround replaced at reasonable cost.

Post the brand of model of both the factory and the Sony radios and we can help with which related parts you may need. The metal sleeve is likely a "DIN" common to many brands.

Doing the work yourself is a good idea, nobody in the car stereo business has the patience this type of repair job requires.

[sbarc]

Originally Posted by Danglerb

Lacking all bass... yipes .... on mine that meant all the front speakers were bad. The paper of the cone was intact, but nothing was left of the surround, the foam or rubber ring that attaches the cone to the metal speaker basket. No surround means no seal, and that means no bass. It is possible to have the surround replaced at reasonable cost.

Post the brand of model of both the factory and the Sony radios and we can help with which related parts you may need. The metal sleeve is likely a "DIN" common to many brands.

Doing the work yourself is a good idea, nobody in the car stereo business has the patience this type of repair job requires.

The aftermarket unit is a Sony CDX-F5700 52W x 4
Here's a photo of the aftermarket unit I removed. I must confess I'm not a stereo expert, which means the factory unit will probably satisfy me pretty well once it is running properly. My car does have the factory amp on the passenger side.

[sbarc]

Originally Posted by Alan in AZ

No - but there is a perforated sleve that goes just at the front few inches - the DIN units snap into this for retention. You should be able to find one used - they are common across many Porsche models and aren't specific to Porsche either...

We have an auto wrecker here in town with some 928's......I go there in the next day or so and see what they have.

The magic receptacle is a DIN socket - you can find plugs & pre built wires in various lengths - check on ebay - they have various numbers of connectors so be careful. This goes from the head unit to the amp and has 4 channels (LF/RF/LR/RR) and the on/off control for the amp. You will need to get a connector for the power - one with wire tails is probably easiest to deal with. It is likely the power connector has ground/battery power/switched power/antenna power/variable illumination - find out which is which - get an online manual for the unit.

In order to work on the stereo install - take off the side panels of the console (esp the passenger side) - they just unscrew - don't even think about doing it just from the front...

Screws?!?!?!? Ahhh....there is screws holding the side consoles panels in place.....removing those will make this much easier.

This is probably the alarm connection that goes to the frame that is missing - alarm is triggered if head unit is removed
These are probably switched and unswitched wires - does one of these have a thin white line - if so thats the switched one. you probably need another with longer wires unless you can remove and add connactors to this one - and know what connectors go where...?

The red wires are both fully red and they run inot a bundle of wire that is wrapped in black cloth electrical tape....which looks like it might be factory original cloth tape....alhtough I really have no clue.

E ...This is the power feed for a power antenna or antenna amp - do you have a powered antenna?

No power antenna....my GT has the short antenna sticking out of the roof.

These are preamp wires not speaker wires. They may possibly have been used as speaker wires -they probably go to your existing amp or an aftermarket amp - check. If there is a DIn plug on the amp do these connect to that? In any case you will need a new DIN connector betwen amp & head unit - trash these. At the amp are the speakers still plugged in - are the speaker wires cut & spliced after the amp or unmolested?

I wonder if I can buy a factory DIN wire that goes from the AMP to the head unit? Would this sort out this whole mess in one stroke?

No just buy a new generic one - on any factory loom you will find - I will guarantee one end is already snipped off just like yours - so it doesn't help you one bit... e.g. http://www.opengroup.com/daddario/FOOA/PW-DIN8-05.shtml (you do not want "mini-DIN" those are computer cables only) - here are the connectors on ebay: http://cgi.ebay.com/Commodore-64-128-8-Pin-DIN-Video-Plug_W0QQitemZ160243617535QQihZ006QQcategoryZ3543Q QrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp163 8Q2em118Q2el1247
Be warned though - these are very hard to solder onto a cable...

Alan

I'm a talented person with a soldering iron......the trick is knowing which wire goes to which pin.

[sbarc]

Here's a photo of what I think is the factory amp next to the right hand side seat. There is a DIN plug, but oddly enough there is no DIN socket on the AMP Is this an aftermarket AMP? The bundle of wires coming out of this AMP loos very much like the same wires coming out of the SONY head unit I just removed.

So what is the quickest, easiest way to sort out this mess? I want to do it right so cost is a secondary concern.

[Alan in AZ]

That doen't look like a factory amp (small though) - it may be fine to continue to use it ... however you will need to validate why you have bad bass before you decide if you are goiing to keep it - it may indeed be due to the speakers as Danglerb says above.

Since you have the DIN plug that end unused (its not just chopped off is it?) you may want to try to strip that whole cable out (back to the head unit)and reverse it - use the DIN plug on the head end and if its long enough (should be) - add RCA connectors to feed the amp on the other end. Not sure where Porsche routed that audio connection...? The RCA connectors are easily available even right angle ones!

If you want to go back to a stock amp you will need more work... but this amp is probably an improvement...

Alan

[sbarc]

I'm keen to dump this aftermarket AMP and pick up a factory AMP. I'd like to eventually get this mess back to how it looked when it left the factory.

I'll also be checking out the speakers once the OEM stereo and aMP are operating properly.

Thanks for all the help so far guys. You are moving my thought process along at a much faster rate than I would have been able to do on my own.

Steve B

[medipedicman]

I removed a factory amp yesterday from a 1983 S model. I was going in the other direction, albeit with a newer Blaupunct. Something to do with ground and aftermarket speakers, but I was unable to use the functioning amp with my new set up.

$50 plus shipping.
PM me your info.

[bgibby]

I have the factory amp & some of the wiring to/from the factory deck removed from my low-mile 90GT. Email if you're interested & I'll look to see exactly what I have. It was all working when I removed it.

Brian