double din a4 cabriolet installation..

toy car hunter

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Oct 30, 2014
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can anyone offer what the below mentions? has anyone fitted a double din aftermarket headunit? and what problems did you find with the installation?

il copy and paste it incase the link does not work.

2004 Audi A4 Convertible

Yesterday I began replacement of the Symphony OEM radio with a DVD/GPS unit I bought from ebay. You may have seen these Head units all over ebay..they look OEM and claim to be plug and play. They may be on some systems but as for the standard SYMPHONY radio, there was nothing plug and play about it. But I am going to try and guide you through the install so if you buy one of these units, you will not have to spend as much time as i did trying to figure out where everything goes so you can fabricate your wiring harness.

The first pictures I am going to post is of my OEM symphony headunit and the back showing the plug configuration. Apparently, there are a few different configurations depending on the radio you have..mine being just the plain symphony, requires CAN-BUS to control the radio.

You would think this would not be a problem when replacing the head unit, but it is a problem unless you buy a radio that has the capability of Can-Bus. This new head unit came with a Can Bus Decoder with Audi software in it. The Can-BUS controls the radio turning on when you turn ignition key forward. Without Can-bus, there is no accy wire to power up your aftermarket radio. You have only a Hot wire that remains hot from battery all the time. In short, CAN BUS decoder will power on your head unit, it will control lamp illumination when you turn your lights on, it will sense your emergency brake, and reverse, and othe functions by using data transmission between car and decoder box. I don't think all audi a4's use Can BUS for the radio but the plain symphony radio does. Yes you could completely bypass the Can BUS but you will go fishing for an accy hot wire through switch, you will have to find a lamp illumination wire to feed your unit, and find your ebrake wiring, and you will be running wires everywhere. If you maintain the CAN BUS, you will not have to run ANY of these wires down.

First pics here are of symphony front and back and key removal of radio and of the new head unit with accessories. I will post more pics with further discription in future posts. I apologize for the headunit picture being upside down..
Notice the rear of the symphony. The top plug in contains the Can Bus high and low, and the front and rear speaker line out and terminal to power factory amps. The plug in the car that fits in that slot will have to be spliced into in order to gain access to can bus and the factory amps and line outs to speakers because there is no pigtail that comes with this dvd/gps unit to plug into the factory harness. The other factory harness plugs will plug into the harness you are going to make from the two harnesses given in the kit.

Ok, the first picture on this post is directly off the top of the Audi Symphony OEM radio so you can see what each pin purpose is on your oem plugs.

The top connector on the diagram is your black connector harness in your car and the second one down is the Brown connector in your car, the third bottom one down is a black 20 pin connector that contains your can bus and line out speaker wires going to factory amps. You will need to splice into the wires on the back of the bottom 20 pin connector as previously stated.

The second picture is of the connector end on one of the supplied harnesses with this kit. If you have the symphony radio, you will NOT use this plug as pictured but you WILL be using the harness attached to this plug as this is the Can Bus harness. You will need to Cut each wire from this plug so you can use the harness with the correct included connector shown in the third picture. The third pictured connector will be used after you cut the harness away from it. Make sure you leave about 3 inches or more of wires coming out of the back of this connector so you will have something to solder to. So lets rephrase what we have said..The harness that has the 2nd pictured plug on the end of it will be our harness but we must cut this connector off and throw it away, it is useless to us. The connector in the third picture is the one we need but we must cut the harness away from this connector and discard that harness, but make sure we leave about 3 inches to solder to the other said harness.

Now, in the first picture, the top plug shows a + terminal and a - terminal. That is the only two terminals you will use on this plug. you will need to move the pin that has the yellow wire on third picture connector so that it lines up with the + on your car factory black plug..that wire will be Red in your car. Then move the black wire pin on third pictured connector to line up with the - terminal on factory black plug in car..that wire is brown in your on connector. Thats it for that connector it is done! You can see the finished plug in on the third picture..see the two pins for power and ground..and for the other side..these are for your front speakers on dash..This is simple..just take the Can bus harness that you have cut away from the other plug and match the purple to purple, white to white, dark green to dark green, and gray to gray and the the striped colors to each other likewise. Solder those to the third picture connector. you are done with that harness now so heat shrink or tape up your solder. You should have TWO wires left coming out of the CAN BUS interface box that are light green and light green with black stripe. These are the Can BUS L and CAN BUS H you will use to tie into the 20 pin black plug in your car.
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I'm going to re check my work tomorrow I have power just not sound period. The previous owner had **** cut everywhere and just kinda threw the symphony system back into it. I think my stock amp is not wired correctly. I'll let you know how it goes thanks for the great info!

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