Yes, it's another one of "those" threads. I will be very detailed about my problem in order to avoid any confusion as to what the issue is. As usual, I have attempted another DIY and encountered problems. I have a 2005 Audi A4 1.8T without Bose, and I recently installed a Pioneer AVH-P2300DVD aftermarket head unit. The installation was going great until I had everything installed and then found out that my rear speakers did not work. If you have ever messed with the dash kit that I purchased, you probably are aware that once the kit is in, it's next to impossible to remove without breaking. I actually removed all but the entire dash just to try and access it without breaking anything, and was fairly unsuccessful. I finally managed to remove it, which involved taking a flathead screwdriver and inserting it precisely into he tabs of the dash kit (unsnapping the trim piece from the snap-in frame that encompasses the had unit).

I have purchased the Metra dash kit:

02-08 AUDI A4 RADIO INSTALL STEREO DASH KIT COMBO 9107B | eBay

Basically, I was under the impression that, with the "Metra amp integration wire harness," I would not have to worry about the seperate amp for the rear speakers (as the amp integration wire harness should have solved that problem).

From what I have read, the front speakers (both left and right) are powered by the aftermarket head unit's built-in amp, and then the rear speakers (both left and right) are powered by the Audi's factory amp (by means of the amp integration wire harness).

I am aware that this topic has been covered numerous times, but it seems as though nobody has actually discovered a solution to the problem without either bypassing the amp (which, shouldn't be neccessary/I am trying to avoid), or randomness (in one thread, somebody wired the front speakers last and then the rear speakers all of the sudden worked). I have searched, and searched, and nothing suggested by others has worked thus far (I even tried wiring the front speakers last like the "lucky" guy did).

Here is that thread (B5 forum, yes, but same exact problem):

https://www.audiforums.com/forum/b5-...oblems-165558/

What I would really like to know, is why the amp integration harness did not function properly; it's highly unlikely that I received a "dud," as this has been the supposed culprit in other cases and proven not to be the issue.

Anyways, here's where I'm at currently:

The head unit is installed and functioning properly, the RCA wires from the Metra amp integration harness are plugged into the back of my Pioneer AVH-P2300DVD (L IN = Green, R IN = Purple - as suggested by the head unit's user manual), yet still no sound from the rear speakers. I have even tried adjusting the actual head unit's sound settings (as suggested on page 47 of the user manual). When I unplug and plug the RCA cables into the back of the head unit, static can be heard from the rear speakers (proof of a signal). So I'm thinking that the amp is getting a signal, just maybe not the right one.

Is there, perhaps, a device that would bypass the factory amp by means of plug-and-play RCA hook-ups and such? If I have to bypass the factory amp, I probably will not be attempting it myself as I would rather avoid the risk of damaging something. I have installed head units in the past, but I have never encountered this problem.

Would this solve my problem?

PAC Audi Radio Integration Adapter Allows aftermarket radio installation in select 2005-up Audi vehicles (model C2R-AUDI) at Crutchfield.com

I did not buy this originally because the dash-kit I ordered was supposed to have everything that I needed, and this device seemed geared more towards a head unit with a back-up camera, etc. Also, the majority of this kit (the wiring harnesses) look identical to the one provided in my kit, which has put me in the position that I am currently in.

Thanks in advance for any help. I appreciate it.

-Will

 

Anyone?

 

Ok, so I have an idea. I was looking at the wiring diagram located on the label of the OEM head unit, and comparing the pins/prongs inside of the harness. I compared the pins/prongs of the Metra amp integration harness to the factory OEM harness and everything matches up.

RF = RF (white wire) - unused
RR = RR (green wire)
+ = blue remote-wire (positive)
Comm. (ground) = negative (ground) (black wire)
LF = LF (gray wire) - unused
LR = LR (purple wire)

The RCA cables that plug into the rear output RCA inserts on the back of the head unit are matched up correctly (green to RR, purple to LR).

I am thinking that perhaps the ground used for the head unit harness needs to be the same as the ground for the Metra amp integration harness (wired to the RCA rear output cables for the front and rear output) that plug into the back of the head unit. Considering that the rear speakers have a seperate amp with what appears to be a seperate power (the blue remote wire from the aftermarket head unit plugs into the blue remote wire in the Metra amp integration unit; which is used to turn on the amp for the rear speakers) and ground than the head unit, I suppose it would be considered an isolated ground (yet on the back of the wiring layout label located on the head unit, it refers to the ground for the line outputs as "comm." for "common ground," I would assume. Perhaps the two harnesses use the same common ground, only, they are split into two seperate harnesses? If that's not the case, then what if I was to tap the ground (black wire running from the Metra amp integration harness) into the ground (black wire) running from the head unit harness to the OEM harness? Then, all speakers wires would have the same ground, but perhaps different power sources (I believe that the built-in amp in the head unit powers the front speakers, thus, they would have a different power source than the rear speakers--which are powered by the rear amp). I have also read that modern head units do not use a common ground, but rather, isolated grounds (which would make sense because most modern vehicles have seperate amps for their speakers--or at least the Bose and non-Bose systems installed in our cars do). This is all sounds very contradictory, yes. It has been rather confusing.

The idea of a common ground possibly being essential was derived from this thread:

https://www.audiforums.com/forum/b5-...new-hu-165821/

Refer to post #4...it says:

"The factory non-Bose system uses a seperate amplifier for the rear speakers; it is mounted on the side of the driver-side rear speaker. While it does appear from looking at the head unit harness that there are four sets of speaker-level wires headed out, in fact two of them do not do anything because the rear speakers are run by a set of line-level wires which go to the rear amp. So, if you just take the harness adapter and plug in your aftermarket head unit, there will not actually be any signal sent to the rear speakers.

In my car, I had replaced all four speakers rather than just the fronts, and rather than screw around with trying to use the factory wiring (which if memory serves involves a common ground - anyone can feel free to correct me on that, I'm not 100%), what I did was to just run a new set of wires back from my head unit to the rear deck. It was easy enough; just tuck 'em up under the passenger side of the dash, then under the kick panel and then the door sills all the way back to the rear seat (you'll want to remove the rear seat bottom cushion and side bolsters - if you don't know how, there is [or was back in the day] a bunch of DIY's on AudiWorld on how to take apart various parts of the interior). I would suggest running both sets of rear speaker wires down the passenger side, since if you ever add a subwoofer you'll want to run the power line down the driver side since the fuse box is under the driver side of the dash. Once you've run the lines, should be easy enough to hook them up by bypassing the amp or just install new rear speakers as well - up to you."

Now, refer to post #5...it says:

"Seriously though, there's no need to run new wire as the old wire will suffice. If you are using a wiring harness then it's very simple. Your wiring harness 'should' come with 2 sets of RCA inputs. Hook up the RCA rear out of your deck to the RCA rear in of your new wiring harness. Make sure to attach the blue remote wire from your new deck to the remote wire on the wiring harness. On the OEM side, this is the white wire. This alone should get you sound assuming your deck is wired correctly. If you snipped your OEM wiring harness then it's a little more complicated. You essentially need to rewire the low level inputs of your amp with a pair of RCA plugs by stripping the ends off and wiring them up to the corresponding wires from your new harness and then plugging them into the output of your new deck."

So, from what these two people have said, you can see where I get the idea of using the OEM head unit's ground for the OEM rear speakers amp's ground. It's in the interest of a "common ground," as opposed to what I believe to be the isolated ground currently utilized by the rear amp.

I will probably attempt to do this tomorrow, as I have basically tried everything else aside from running wires directly to the rear amp (which seems unecessary).

If anyone would like to see pictures of the harness(es), refer to this thread (particularly posts #20, #25, #27, and #29):

https://www.audiforums.com/forum/b5-...-165558/page2/

It also has the picture of the label for the OEM head unit's wiring diagram.

Any input would be greatly appreciated. Thanks.

 

Update:

I have solved the problem. As it turns out, everything was installed correctly; except I had the RCA cables from the Metra amp integration harness plugged in the wrong RCA ports on that back of the head unit. Also, I had to go into the head unit's settings and adjust the rear outputs to receive signal from the subwoofer RCA ports (it was not a simple mix up--there were many variations that needed to be tested before concluding with the only successful one).

Basically, there were ports for subwoofer left and subwoofer right, front left and front right, and then misc. input ports. I hadn't given much thought to plugging the RCA cables for the rear speakers into the subwoofer ports because I figured those were reserved for, well, subwoofers (common sense). However, as mentioned above, I did end up plugging the RCA cables into the subwoofer left and subwoofer right ports.

Hopefully anyone who reads this will learn to triple-check their connections before suspecting another issue. I had checked mine over and over and was fairly certain that everything was correct. In fact, I had previously even plugged the RCA cables in every possible port to see if I could get sound from the rear speakers; yet I was unsuccessful. It was not until I plugged the RCA cables in another port and adjusted the head unit's settings for rear speaker outputs, etc. that I found my answer. Instead of dwelling on the wasted time, I will call it a day and be happy with my successful installation (finally).

I also purchased aftermarket speakers (four Kicker DS60 6.5" speakers); I think I will have them installed professionally. At least I was able to save money by installing my own head unit.

So, in conclusion, when installing the Pioneer AVH-P2300DVD, it is essential that, after making all of the necessary wiring connections, you must change a few of the head unit settings. For those of you with this unit (or perhaps even a similar unit--this may work for you also), this is what you need to do:

[Note: these instructions I am providing to you below exclude basic wiring information; if you have questions about the basic wiring, details on the wiring are available in numerous other threads. If you have ever installed a head unit in the past, the installation part should not be a problem for you at all].

[Disclaimer: everything here or in any way referenced here is what I have discovered from my personal experiences with this installation (including research information obtained from others via various threads, etc.); under no circumstances should I be held accountable for any problems you encounter as the result of information provided by anything I have mentioned. It is your car, your responsibility. If you lack the experience necessary to complete such an installation, and you don't mind paying installation costs, having a professional install may be your best option; for those with experience and/or those of you brave enough to tackle this install yourself, I wish you the best of luck, and I hope that my write-up benefits your installation in some manner].

[Note: be sure to figure out the e-brake wire (whether you connect the wire as it is supposed to be, or bypass it) before you complete your install; otherwise you will not be able to watch DVDs on your head unit. More information about that is listed below under "optional"].

So, with that being said, let's get started. As mentioned above, the more common information (such as the basic aftermarket head unit wiring) is available on various other threads, and (if you have the Metra kit) instructions should have already been provided for those aspects of the install.

(With the negative battery terminal disconnected--as it should always be when working with electrical components of your car)

1) Connect up (plug in) the OEM harnesses with the harnesses that you have wired up from your head unit to your Metra wiring harnesses (after you have already spliced your wires going from the head unit's harness to the Metra's harness, of course). There will be three OEM harnesses: two black, and one brown. There will also be the antenna wire (if you purchased the Metra dash kit that I did, it should come with an adapter for the antenna). One black, and the brown will plug into the black Metra wiring harness. The other black (for the rear speakers and their amp) will be connected to the red Metra wiring harness [Note: be sure to plug the green and purple RCA cables (coming from the red Metra wiring harness) to the subwoofer left and subwoofer white RCA ports on the back of the Pioneer AVH-P2300DVD head unit]. Connecting these harnesses (OEM to Metra) is pretty straight forward. There's no need to worry about mixing them up because if that were the case, they simply would not fit. Each harness has a little groove where it meets the other perfectly and clicks into place.

2) Once everything is connected safely, reconnect the battery terminal.

3) Turn the ignition to "on." The head unit should power on. The head unit will be in "demo" mode upon initial start-up.

4) Press the "menu" button on the head unit. Select "rear speakers." Once in the "rear speakers" menu, change the top to "subwoofer" and the bottom to "rear" (if you have the RCA cables plugged into the subwoofer left and subwoofer right ports as I have indicated above). If you are unsure of your connections, the green should be plugged into the "subwoofer right" port (bottom) and the purple should be plugged into the "subwoofer left" port (top).

5) Select a source for music (to do this, simply press the "source" button on the head unit until the desired source has been navigated to). I tested the speakers using the radio as my source. I switched the tuner to a local radio station that came in clearly, and sound could be heard from all speakers. To verify that all speakers are playing, use the fader controls to adjust the audio to the rear (if no sound is coming from the front speakers, that should be fairly obvious). To verify that the rear speakers were playing correctly, I used the fader control and turned it all the way to the rear until no sound could be heard from the front speakers (level 15). Then, I turned up the volume for the rear speakers. The sound came in perfectly (what a relief).

6) When you have verified that all of your connections are correct, everything on your head unit functions, and sound comes in correctly, you should be safe to push the head unit into the dash [Note: be 100% sure that everything is installed correctly before completing the dash kit install--I had mine in all of the way, and it was next to impossible to remove once I realized that no sound was coming from the rear speakers]. Basically, once they're in, they're in for good. It's very hard to pull back out without breaking anything. I had actually taken my dash apart to re-access it just to avoid breaking anything; not fun at all.

7) Enjoy your new head unit! Thank you for taking time to read my thread.

--Optional--

In my car, I have installed a bypass for the e-brake wire used for DVD playing purposes. If you are going to do the bypass, please go about using it responsibly. From what I understand, it is prohibited in most, if not all states. It is very unsafe to be playing a movie while driving; I simply did it to have that option available. It would be good for my passengers on long-trips and such to be able to watch a movie while the car is moving. Use your better judgement, please.

From what I understand, the e-brake wire (light green wire coming from the Pioneer AVH-P2300DVD head unit harness) functions as a means of detecting when the car is in motion. It is to be connected to the e-brake wire in the car in order to detect when the e-brake (emergency brake) is applied. There are numerous threads, and various videos (on Youtube) with instructions on how to bypass the e-brake wire. The general concept is that when the head unit is powered on, the head unit's e-brake wire receives power; this power must be grounded. However, the power cannot be grounded until after the head unit is powered on (thus the need for a bypass). Otherwise, you would simply be able to ground the head unit's e-brake wire and call it a day (this is the case for some head units, but not the Pioneer AVH-P2300DVD that I installed). So basically, the sequence is ON-OFF-ON.

For my car, I went to the local Advanced Auto store and purchased a 15 amp toggle switch (on/off) with two prongs. I also purchased connectors, and ground wire. To make the switch, I spliced a ground wire into the ground wire being used for the aftermarket head unit (the black wire from the Metra harness to the head unit's harness). To splice the ground wire (for the bypass) into the existing ground wire (for the head unit) I cut the ground wire in half and used one of the twistable cone wire connectors to join the three wires together (each end of the existing ground wire, and the one end of the ground wire for the bypass). I ran the new ground wire into the glove box, and hooked it to one of the prongs on the switch that I purchased. I then ran the light green e-brake wire from the head unit to the glove box, and hooked it ip to the other prong on the switch that I purchased. With everything wired up correctly, I reconnected the nagative battery terminal and tested out the new switch. I turned the ignition to "on," the head unit powered up. I inserted a DVD, and got the message indicating that playing DVDs while the vehicle is in motion is prohibited. I flipped the switch one or two times (should be sufficient), and a new message came up (you will know when that new message appears--it's clearly different from the first). I pressed "ok," and the DVD played fine.

Here is one of the articles that I read on the bypass switch:

http://www.ehow.com/how_4482151_ebra...vd-player.html

There are also articles available for bypass relays, etc. There are even kits that you can buy for fairly cheap if you don't want to make your own.

Stay safe, everyone.