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CDR-24 replacement for double DIN Pioneer DMH-W2770NEX

283 Views 4 Replies 3 Participants Last post by  Seijinn

I purchased a double din Pioneer DMH-W2770NEX and want to replace my CDR-24 radio on my 2005 Boxster it doesnt have the bose system but I am not sure if it have the Sound Package Plus (SSP) or not.

I am trying to understand and confirm where each wire connects but I still have some unknown, some help from someone who have done similar would be great :)

attached the CDR-24 pinout and below the online manual for the DMH-W2770NEX


The wires available that was connected to the CDR-24 are:

Connector A
- A2 red/black - 12V Switched output
- A4 Red/Green - 12V Battery Power Input
- A5 White - 12V switched Output
- A8 Brown - Ground

Connector B
- 8 Speaker output wire to connect to the DMH speaker wires

Connector C
- C1 Yellow/Blue
- C2 Red/White
- C4 Bleu/Black
- C20 On/Off Input

The wires I need to connect for the DMH-W2770NEX are:

- Yellow wire - Need constant power - Connect to A4 Red/Green 12V Battery Power Input ?
- Red Wire - Need Key on/off switch - Connect to A2 12V Switched output ?
- Black Wire - Need Ground - Connect to frame or A8 Brown ground ?
- Purple/White - Reverse Gear on/off - Run a wire and Connect to 12V+ backup lamp, what the best location ?
- Light Green - Parking Brake on/off/on Switch - Run a wire and Connect to parking brake power supply switch ?
- Blue/White - System Remote Control - can be Skipped, how do I confirm if I have an amplifier it need to connect to ?
- Yellow/Black - External Mute - Can be Skipped, or where can this be connected ?
- Orange/White - Illumination - Can be Skipped, or where can this be connected ?

thanks a lot!


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Welcome to Planet-9, the Friendly Porsche Forum...

A few questions:
  • Do you intend to splice into the existing wiring on the car?
  • Will you be using an adaptor or hacking/cutting/splicing?

And some comments:
- You've added a PDF that's labeled as CDR-24 Pinout?

Here is what that PDF shows:

Font Rectangle Parallel Pattern Number

(I left off the notes, but perhaps I'll add them..)

Font Screenshot Electric blue Document

The diagram is quite clear on INPUT and OUTPUT.

OUTPUT means that the electricity is coming FROM THE CDR24.
INPUT means the electricity is going into the CDR24.

A2 is switched power OUTPUT - so the CDR24 provides 12V on this wire when the CDR24 is turned on. It sends that 12V off to something that needs power like an ASK amplifier (if one is part of the system.) That might be used by another device as a trigger to turn it on. Notes 1 and 3 explain that (which is why they sent you to them..) So - no this isn't a good choice for power that's switched by the ignition key. Absent the CDR24 that terminal will be basically dead. A7 - "Switched Battery Input" would be much more suitable for this application.

Your black wire - ground - can go to a chassis ground OR as you determined the brown wire in the harness.

Your Purple/White wire - the video trigger for a reversing camera - only is needed IF you are adding a backup camera. And yes - I tapped mine off using a Positap the wiring going to the starboard side taillight assembly. That should work. Most backup camera wiring setups use a coaxial cable for the video signal and they include a "traveler" - which is a red wire inside the coax that can be connected to the backup light at the rear of the camera and has an output coming out at the other end, which will be behind the radio. It's made for exactly this situation - providing a trigger signal to the headunit to switch it to backup-video mode.

Your light-green, parking brake signal. That is a wire that will enable playing video when the parking brake is engaged. Most people simply ground it, which enables playing videos whenever you want to (but I'd suggest not playing it whilst driving.) So - that one could join the black wire going to ground...

The blue/white wire - system remote control - I'd assume is used to trigger external devices like an amplifier - and guess what? Since you're not using A2 for anything - that's where that wire belongs. If you have an amplifier it will turn it on. If you don't have an amplifier it won't do anything at all, so the connection only has an upside, no downside. blue/white to A2. Easy.

The final two - I'd ignore them. Why would you want to trigger a "mute" - if you're doing phone through it - that's already done inside the unit?


OK - now onto some other things:

1 - Embedding PDF's - is generally a don't do it here sort of thing. The reason being it requires someone trying to HELP you to download a potentially virus-laced file. Most of us simply won't do that. Do what I did (I had a clean copy of that file) - open the file, then use a screen capture program to capture and resize the section that's significant to your question and paste it into the thread. No need to open anything. No risk of viruses.

2 - Have you already purchased this headunit? If you haven't - or if it's returnable - you might want to consider Outstanding Tech Contribution! - DIY on installing an... - which is a less expensive Android-based unit made specifically for the 987/997 series Porsche.

It fits into the dash like it came from the factory. It's not a 10-minute installation (there are some components you have to mount around the car, like the GPS antenna, the 4G-LTE antenna if you option that, etc..) but it doesn't require hacking up or splicing into the factory wiring on the car. It plugs into that wiring.

Just sayin' - it's cheaper, it has KNOBS, it can do Sirius XM via an Android app, and it does Apple CarPlay and Android Auto. And we know quite a bit about it. There isn't a lot of documentation on it yet - but we're growing that right here.. and you'd save about $200.

IMHO, the biggest downside to the one you're considering - is no knobs. You have to use the touchscreen for something as simple as muting it or turning the volume down. You'll find that distracting and annoying.


If you're already committed to the Pioneer - that's fine, but - I'd strongly suggest getting a plug-in-adaptor for the factory harness that plugs into the cable (where it plugs into the CD24) and has wire stubs coming out of the adaptor to splice to your Pioneer wiring. That way if someone wants to go a route that enables Plug&Play - the wiring is still there and intact for them to use.

If you don't want to spend the $7 or so for the adaptor (they're all over Amazon and eBay) - then spend some money on "Positaps" - these allow you to tap into wiring without destroying it. I do not suggest those damn "StotchLok" splice connectors - they DO destroy the wiring. Only use Positaps. They make ones that go from one size of wiring to a different size. Since Porsche kept the weight down by using skinny wiring the size change ones are really very handy to use.

3 - You haven't introduced yourself. That's sort of tradition here.. you can find where to do it at: New Member Introductions - tell us about you, tell us about your car, and show off the car with some photos!

Looking forward to seeing your intro message, welcome once again to the Friendly Porsche Forum!
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