Radio Wiring

rjc · Apr 3, 2008

Hi Guys

I've removed the after market Kenwood radio from my 964 and intend to fit an old style Blaupunkt radio/cassette unit similar to the original factory fit. On removing the Kenwood I found a small box behind the radio (about 5 inches by 3 inches) that has an ISO radio connector at one end that was connected to the Kenwood. On the other side it has what looks like a 7 pin DIN socket that connects to a cable that disappears up behind the dash. Before I start pulling things apart to see where it goes does anyone know what this small box does? Maybe a feed to a power amplifier? If there is a power amp where is it likely to be located?

(I'm sure I saw a similar thread to this elsewhere on this or one of the other Porsche forums (or is that fora?) but now I can't find it).

Anyone got a 964 radio connections/wiring diagram?

Thanks,

Robin

Dave Wilkinson · Apr 3, 2008

Robin,

The DIN connector is, indeed, the connection to the external amplifier. It should be under the driver's seat.To be honest, it's anybody's guess what has been done to the wiring because the standard fit radio/cassette in the 964 didn't have an ISO connector as far as I know Mine was an absolute mess - and I still haven't found a decent ignition live to wire mine up correctly.

If you need the wiring diagrams, the whole Workshop Manual is now available for download from Rick Cannell's web site (link here). Each volume is separate and the Electrical section contains the radio wiring.

Regards

Dave

kevin · Apr 5, 2008

As above, I had a Blaupunkt amp under the drivers seat....bloody mess of an install though..now corrected.

Kevin

rjc · Apr 8, 2008

Sorry for not acknowledging the responses until now - PC problems!

Thanks for your advice Dave and comments Kevin - I'll investigate further when I get a chance. The Blaupunkt radio unit I've got claims to be 45 watts/channel output which seems more than adequate for direct connection to speakers so I'm minded to remove any external amplifiers altogether and just connect the speakers direct to the radio unit. Do you think that's sensible or would it be better to try and continue to incorporate the external amplifier somehow?

Robin

rjc · Apr 8, 2008

supplementary question - if I want to connect the 4 speakers direct to the back of the radio unit (in the dash) am I likely to have to run additional cables from the location of the booster amp (by the sound of it, under the drivers seat) or might the wiring loom already provide suitable connections somewhere behind the radio opening?

I ask because the wiring diagram seems to imply that at least some of the radio options in the 964 had direct connection to the speakers rather than via a booster amp.

Dave Wilkinson · Apr 8, 2008

Robin,

My car came originally with options 328 (Bremen Radio) and 494 (Amplifier & Rear speakers) and had the multi pin DIN connector at the back of the radio. The Bremen radio/cassette has long gone and the Kenwood unit that was in the car when I bought it had been wired directly to the speakers with new cables. I haven't ever looked under the seat to establish if the amplifier is still there!!!

I suspect most of these cars have, during their long lifetime, been subject to all manner of changes so trying to relate what is there now to what might have been in the beginning might be a thankless task. There certainly were several versions of the radio install but I doubt the wiring harness accomodated all of them. It wouldn't surprise me if there were different harnesses for each type of installation.

Personally, I'd be inclined to run new speaker cables from the head unit and splice them into the extsting cable ends at the amplifier (under the seat). At least you will only have relatively short cable runs - to replace all the way to the speakers might be a much more complicated job. I know the rear speaker cables are a real pain to get to!!!

Regards

Dave

smallspeed · Apr 8, 2008

Mines wired directly, can't comment on whether its a different harness depending on amp/no amp, but im sure someone will know
the way audio kit has moved on you're probably better off bypassing the amp and going straight into the speakers; the amp in my old boxster (with upgrade hifi option) was s**te so I shudder at the thought of the early 90's version!..

Bypassing the amp should be as simple as removing the connector from the amp, and then jumping from speaker inputs to their respective outputs, or if you are certain you will never want to put it back to standard again just cut the wires and join them directly.

I personally would run new wire from the head unit to the front speakers, as its not a big job and some decent quality speaker cable (at the cost of maybe a tenner) will give you a much better sound than the thin gauge wire thats in there as standard. The front speakers should be first to be upgraded anyway, so for the future if you decided to go with some better ones you're all set with the wiring side of things.

Halfords will rip you off, as will most car "superstores" and car audio centres will want to sell you some serious cable which will be little or no benefit to you!.. If you get something around £2 - £3 a meter from richer sounds that should do nicely.. Also they often have "offcuts" of 2m or so which they will sell on the cheap (its too short for around the house but fine in the car)

I'm sure someone will be along soon to give you a more technical response [

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ben

rjc · May 13, 2008

Just an update to let you know what I did in case it's of interest to anyone else.

If you move the drivers seat all the way back you can get sufficiently close to the booster amplifier to be able to disconnect the 4 speaker plugs and the power connector. I then bought 4 x 2 pin speaker DIN line sockets from Maplin, soldered these up to 4 lengths of speaker cable, connected them to the 4 speaker plugs and ran the cables under the carpet back up to the rear of the radio. I did this rather than cut the original cables just in case I later want to recommision the booster amplifier.

I'd already rewired my cigarette lighter socket to be always on so that I can use this to easily connect a battery conditioner for when the vehicle's not in use for a while. So both ignition switched (ex of the cigarette lighter) and permanent 12 volts are readily available to connect to the radio. I didn't forget to connect the little wire for the windscreen aerial booster (it runs alongside the aerial cable) to the radio's switched 12 volt output. Job done. Sounds better than it's ever done and the original booster amp is now redundant.

Thanks for all the advice.

bobster · May 19, 2008

Hi RJC,

I have just sorted out a decent radio for the 964 and dumped the original old Kenwood hash-up wiring in favour of the new required ISO connectors.

I noticed the thin wire running down the aerial lead and assumed it was a ground wire, as I'm sure it was connected that way, so reconnected to the radio earth cable again.

Now I've just come across this thread and noticed you mention what sounds like the same cable should be fed 12V switched.

Can you confirm what colour your cable was please?

Thanks,
Bob.

rjc · May 20, 2008

I'm pretty sure it was black and very thin with a small spade terminal on the end. If you ground it, you won't do any harm but the aerial booster won't work and radio reception will be lousy or non-existent.