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Car Audio Ipod

  1. Aug 7, 2006 #1
    I have a head unit (HU) for my car (Panasonic) with the ability to connect an external CD changer. The HU connection has an 8 pin DIN and a left and right RCA input for the external CD changer. I was hoping I could easily connect the left and right RCAs to my ipod and connect the 12v and ground from the car to the remote turnon in the back of the HU (with a switch inbetween to control ipod/radio). I assume this is all standardized and should be relatively easy to find, but so far have failed to get a reliable source.

    The problem so far is it appears the HU and CD changer manufacturers don't like to give pinouts for their devices.

    Does anyone know where I may be able to find these pinouts? Or simply what pins are Remote Turnon and ground (although I assume ground is the center pin).

    From my searching thus far it appears that 12v DC is what is needed cause the HU to recognize the CD changer (ipod) but I am not 100% on the reliability of the source (questionable forums). Does anybody know if this is correct? Is a ground necessary for the DIN or is having the ground from the 16 pin bracket enough?

    Just to point me in the right direction would be of great help.

    Thanks, D Dean
     
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  3. Aug 7, 2006 #2

    NoTime

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  4. Aug 7, 2006 #3
    I appreciate the link, unfortunately I've been through most of those sites without any success. The problem is my HU, rather than having the 13 pin DIN (which seems to be pretty much standard) has the line-in pins in the RCA form. This means its an 8 pin DIN plus two RCA inputs. I was thinking about buying the converter (13 pin to 8 pin and RCA) and testing it with the pinout from the 13 pin DIN which I have. I will keep searching for the schematic of the converter or the pinout of the 8 pin DIN.

    Thank
    D Dean
     
  5. Aug 8, 2006 #4

    NoTime

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    If you have a DMM and a couple resistors you could just test the pinout.
     
  6. Aug 8, 2006 #5
    Yeah, I was just hoping I wouldn't have to buy the 8 pin and RCA to 13 pin converter at all. Unless are you saying I could somehow test which pins in the HU are which with only the HU, DMM, and a couple resistors?
     
  7. Aug 8, 2006 #6
    Firewire Power

    I have another related question if anyone is interested. I noticed that among the wires coming out of the car fusebox is a 12v power wire. Also, I saw the pinout of the ipod here:

    http://pinouts.ru/Devices/ipod_pinout.shtml

    You can see that there is a Firewire power option which is also 12v (pins 19,20 for positive 12v and 29,30 for gnd). Can anyone see any reason why I couldn't use the 12v and gnd from the car fusebox to power the ipod using the firewire power pins. I assume there is no special handshake protocol or anything like that in order to accept power.

    The reason I want to do this is:
    1. It would be nice to have a free lighter adapter
    2. I've heard that the ground on the cigarette lighter is different from the ground going to the head unit and therefore tends to give a hum if you are playing and charging at the same time.

    Thanks

    D Dean
     
  8. Aug 8, 2006 #7

    NoTime

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    Auto power is 13.5v with some serious spikes in it.
    You would want something to limit it to 12v if you want remote power. I don't know what an ipod can handle without getting cooked. It's possible your HU does this to the connector, but I doubt it.

    On connecter. You know the 13 pin pinout, so subtract the audio since you have RCAs. So whats left to fill up the 8 pin. Power and grounds are easy with DMM.
    What are the ones left over supposed to do?
     
  9. Aug 8, 2006 #8
    Basically what I want to find is the auxilary remote turnon pin in the head unit. Looking at a pinout of the 13 pin DIN it appears as though there is a Mute pin, Acc Out (filtered power)?, Batt Out (filtered power)?, CD Stop, and the aux. Basically in the site below is the 13 pin DIN and what I want to find is the equivalent of pin 6 but in the 8 pin DIN.

    http://www.itsayellow.com/girls/subaru.audio.html

    As far as the power goes, perhaps I could get a 12 volt regulator or something?

    I appreciate the help, and will keep looking for that pinout.

    Thanks

    D Dean
     
  10. Aug 8, 2006 #9
    I'm going to take this over to a car audio forum (don't know why I didn't think about that before). Thanks for you help.

    D Dean
     
  11. Aug 8, 2006 #10

    NoTime

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    Most regulators require a 2v headroom so 13.5v-12v is only 1.5v and with the engine off the car voltage will be very close to 12v. What you probably want is a DC-DC convertor. They do sell these as auto accesories. Not sure what they mean by (filtered power), but if it's 12v with the engine running...

    According to your pinout. Once you figure out which pins are ground or power with DMM the rest are either not connected or are 12v inputs. See if you can get a resistance measurment with the DMM on the remaining ones.
     
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