IanM

I'm wondering if anyone has an electronic copy of the wiring diagrams for a 2004 996 GT3. I have a copy of the 996 technical manuals, but the wiring diagrams are for 1999 - 2000 model year 996's.

I'm currently installing an aftermarket Alpine head unit (I know...and yes the exhaust note of my FVD headers and Europipe exhaust is fantastic). I won't be cutting or splicing into any factory wires, as I want to keep everything original and be able to plug the stock stereo back in. I've got all the various speaker, power and ground wires figured out, but am trying to determine which wires correspond to the:

- antenna amplifier (not even sure if our in-windshield antennas incorporate an amplifier)
- dashboard illumination signal

Thanks!

jittsl

Shows how ignorant I am. I always thought the GT3 had one of those optical circuits that made replacing the stereo nigh on impossible. I listened to the radio once, it was crap and I never turned it on again believing I couldn't do anything about it.

If we don't have the optical loop then I would guess that you should be able to deduce most of the wiring from the earlier cars diagrams that you already have.

IanM

Yes, the CDR-23 has an optical communication port that is used with non-GT3's that have optional accessories such as a cd-changer or Bose amplifier and sound package. It's not used at all in my car, and just has a yellow plug over it. I've deduced most of the wiring already, just trying to figure out the two described above. I'd also like to get my hands on the GT3-specific wiring diagrams in case there are other wiring-related things I want to investigate in the future.

JohnPG

You may find what you're looking for here: http://www.porsche.com/usa/accessori...artscatalogue/

cchan

I replaced my OEM stereo with a Pioneer Avic headunit about a year and a half ago. I got a whole bracket/harness kit but had to move around a few pins on the connector that were different from the default 996 configuration.

The attached files should help answer the antenna wiring. Given my notes, it looks like I didn't find any illumination signal on the harness so IIRC I think I must have given up and tapped one of the lighting wires. Probably from the cig lighter or one of the horseshoe switches, or maybe from the A/C control unit. I also didn't want to splice anything if at all possible, but can't remember how I solved that one.

SoCalDan

Hi,
I installed an Alpine unit in my '04 GT3 about a year ago. I purchased it from Crutchfield and used the documents cchan installed above and anything else I could get my hands on. After everything was ready to install, there was one wire missing. I believe it was the constant power. The regular 996, Boxster and perhaps even the Turbo have this wire running to the stereo, but the GT3 doesn't. I had to splice into the fuse box and run a cable from underneath the steering bracket (above the pedals) to behind the center console and into the back of the stereo unit. The used a fuse doubler and tapped into the AC unit so that I reverse the installation at anytime. The unit has worked flawlessly since and I've also used the same system to install my V1 up my the rear view mirror.

I hope my explanation made sense.

-Dan

IanM

Thanks very much guys, that's a big help. My plan is to install the stereo tomorrow.

IanM

Thought I'd follow up on this. The stereo installation went flawlessly, I was able to significantly upgrade the system without adding or cutting any under-dash wires and without any other visible changes (other than the new head unit).

I went with an Alpine CDA-117 head unit and an Alpine KTP-445 in-line amplifier. The amp is incredibly small and light, and plugs in series between the stereo and the connector that normally goes into the stereo. This amp raises the speaker outputs from 18W RMS x 4 to 45W RMS x 4. I installed the amp in the area under / behind the glovebox.

For speakers, I chose Focal 100 VRS component speakers for the dash (4" mids and tweeters). For the back I installed a pair of CDT ES-4 4" midbass subwoofers. The speakers all fit inside the stock speaker covers, which had to be modified on the insides.

For the marginal (I'm guessing about 4 lbs) weight gain over the stock stereo and speakers, the sound is really incredible, a huge difference from stock. I can also now listen to music from an ipod or memory stick, through the USB plug that comes out the back of the head unit. Maybe I'll install a slightly lighter battery when my current one dies, and will be about even again. Or I could use to lose 5 lbs myself...

BTW, I now have a pair of brand new Focal IC 100 coaxial speakers that I didn't end up using, would make a great upgrade to your front speakers if anyone's interested in them.

kk2

Nice.. What was your total cost to diy?

kk2

Also, did you use the install kit from a boxster?

IanM

Total cost was just over $1000. About half that was for the front Focal speakers. Would be much cheaper with less expensive coaxial fronts. I bought pretty much everything from Crutchfield, Amazon, and CDT Audio. I think the head unit wiring harness was for an Audi, I ended up buying two because I wanted extra pin-connector wires for wiring-in the rear speakers. The kit comes with two plugs, you don't need the one with the rca plugs. Just go to Crutchfield and enter the following numbers into their search box.

12040EU10
Antenna Adapter

120701787
Audi Wiring Harness

IanM

Below are a couple photos of the Focal IC 100 speakers that I am selling (4" 2-way coaxials). They're brand new, never installed. I did contemplate installing them in the rear of my car, but I decided not to put coaxials back there as the tweeters in the front are more than enough. I did plug them in and they would be a huge upgrade in the front even with no other changes (with stock stereo and rear speakers). Will sell for $125 plus shipping.

Here's a good tutorial on how to install them in the dash -

IanM

photos

Mike in CO

PM sent

kk2

Awesome.. Thanks for the info. Not sure how interested I am in doing this yet, but the info is appreciated.