Looking more carefully at the schematic, it appears to be less simple than my original (somewhat cocky) assumptions.... let me investigate a bit and I'll respond with a more educated analysis.

I do hope, now, that the two signals ARE summed or selected in the amp, and its imminent arrival will take care of your problem. I'll have a better answer for you soon.

 

OKAY, I now know what you were experiencing and why, with your swapping of cables.

Stereo audio - from the head unit, is passed along to all systems thru the green (right), black (ground) and blue (left) wires in every AINet cable. The NAV audio is passed via the other connector, IC12 at the nav unit, Green (nav audio +) and yellow (nav audio -).

By unplugging the head unit's AInet connector and plugging into the amp directly, you were still sending head audio to the amp, directly instead of thru the Nav first, and the nav voice audio still got there it's normal way - through the other cable/connector pair.

This means that the selection between nav and head unit audio is done in the amp - or at least they are summed there - so a fault in the head-unit audio, front end section of the Amplifier could cause your white noise symptoms.

What I don't understand is how the Nav unit was doing anything, with the AINet disconnected - I don't see any other connections that could be passing commands to it... strange but we'll probably get to the bottom of it eventually. Will the Nav System generate unsolicited voice messages, without your pressing keys on the head unit (or some other user interface?) If so, this explains the voice... but you shouldn't be able to control it, or see any data from it, without the AINet cable connection.

Where does the nav normally display data - in the center of the head unit where radio and CD info is shown? Does it show a map? (i have zero knowledge of the nav in the jag).

In your experiment, was the nav audio talking over the top of music ( where normally, the music would be muted or volume reduced)? I suspect that the nav unit would perform the muting or vol reduction functions (when the nav voice is in use) and then pass the modified head audio along to the amp - where the two (music and nav voice) are summed. Not having Nav, I don't have a handle on the system's functions nor on the interoperability between the head unit and the Nav system.


What this DOES tell me, however, I that I can likely buy a used Nav unit, plug it in and (likely with some other electronic gymnastics) have it work in my car. I see one for $100 right now... all I have to figure out is where/how to get a DVD for it, and whatever other issues may pop up.

Anyway, that's as far as I've gotten so far, by looking at the diagrams.

It does look as if the problem you're seeing should be in the amp... Thanks for letting me keep my paycheck.

 

@QuadManiac:

Thanks for the additional analysis.

I couldn't agree with you about how bizarre this is. But let me clarify: Everything (I mean everything) works exactly as it did. The Nav prompts "unsolicited" as I drive; I can successfully recall the list of recent addresses, choose one, and get turn-by-turn visual instructions (on the CD/TAPE/RADIO green-backlit display), etc.; I can fully interact with the Nav unit in every conceivable way, as before. The voice prompts continue to "dim" the audio already playing when necessary.

That's why I went back to the trunk to see if a Gremlin had reconnected everything just to mess with me! I can assure you that I confirmed that the AI-Net cable from the Nav to the Amp is indeed dangling-free in all its glory.

This tells me that Alpine duped me into believing that AI-Net carries all data exclusively on their premium sound bus. Obviously, those Molex-like connectors (what are they actually called?) must be communicating data and not just audio to/from the Nav and Head Unit.

As I mentioned, the AI-Net connection on the Nav unit seems to be simply a pass-through.

I thought later about why it might be this way and perhaps it is for this reason: Perhaps other AI-Net modules were intended to "snap on" to this premium sound system--so Alpine required all devices on the AI-Net bus to daisy-chain to each other on their way to the amp. This would require all devices to be attached to the bus--whether or not they need information from it or contribute information to it (sort of like a Christmas-light setup in which one strand is simply an extension cord with no lights on it).

But I did not expect that and now I do not understand why Alpine would not have used AI-Net to communicate Nav information to/from the Head Unit! I mean, they created this proprietary data bus--now why not use it for Nav information?

I do see data DVDs for this Nav unit listed occasionally on eBay. The unfortunate thing is that the data discs stopped getting updated after about year 2002--so you might be better off buying a Nav unit that's portable (you can then use it when you rent a car or ride a bicycle/motorcycle) rather than spending on the Jag Nav. But that's obviously a personal decision. I must admit that it is cool to have it all integrated in the car and with the Head Unit, of course.

The new Amp will soon arrive and I will be around during the day to grab it and install it. I am very eager to see if it works. By the way, I had opened my current Amp (as described in a much earlier post) and re-soldered all of the connections behind the internal heat-sink (I did this because they appeared a bit "chalky")--but I do not believe I re-soldered behind any of the external connectors. I may give that a try while I wait for the new Amp to arrive.

Thanks again--I'll keep you posted.

Regards,
Jon

 

I agree with your synopsis, but what is more confusing is the fact that the wiring diagram only shows 3 wires from the Nav to Amp on that molex conn in premium sound... audio+, audio- and ground... it also shows 3 (different) wires from that same connector returning to the radio, for standard sound, but labeled as the same signals - audio +&- and ground.

Where would the command signals be transmitted? Only thing I can think of is if the 3 wires in that 'molex' connector to the head are used for data comms when in premium sound configuration. Unless the wiring diagram has left some connections out, this must be the answer.

Allso, I've heard in this forum that the radio has a 'standard' or 'premium' switch on the back. Perhaps this changes the usage of those 3 connections relative to the head, nav and amp (in addition to anything else necessary)? You have a head unit out of the car - does it have this switch? Also does the molex at the Nav have leads that go to the amp, or only to the head,or both?

Relative to the mod to nav for my car - i'd like to have it just for the 'cool' factor... i already have several portable gps navigation systems - including my cell phone... But, can you tell me, does a map show up on the stock radio display, or just written directions, arrows, etc.?

 

@Quad

You get arrows and the road name, and thats it. The stereo display is so low down in the dash that I find it impossible to look down safely. I use Tomtom on my phone, which sits in a cradle mount on the left hand side of the dash so it's almost at eye level, so it's a lot easier to see it, plus of course tomtom 3d colour maps are a little bit easier to read :-)

Anyway, I understand the cool factor thingy, so if you do get the nav upgrade, I can make you a North America 2000 map DVD if you like as I have my original

 

Sorry, I forgot to answer that question... To add to what SARC wrote, the display shows only the simplest graphics and can, when needed, display surprisingly complex graphics (such as which exit to take in a traffic circle). I agree that it is difficult to read the display while driving but the audio prompts are generally good enough that I rarely look at the display other than to see how many feet I am to the next turn (when many turns are available it can get confusing, so know that the correct turn is still 200 feet away can make the difference between taking a wrong turn to soon and taking the correct turn).

I happen to really like the Jaguar Alpine navigation unit's soothing voice prompts and have fallen completely in love with the woman who gives them (she has gotten me out of many a navigation-pickle over the years).

Regards,
Jon

 

Thanks for the description. Where do they hide the GPS antenna? Any new amp news yet?

 

Quad

If you end up getting a nav unit let us know. Sounds like an interesting option.

 

No news yet on the new amp--I'm still waiting for it to arrive.

I don't know where the GPS antenna is... Does anyone else here know?

By the way, the GPS voice is a real woman's voice (with a neutral American accent) recorded at a very high bitrate--it is not, as it is in many other units, a digitized or synthesized voice.

Regards,
Jon

 

Yes, I do want tto add his... especially because of the voice.

But several things will need to be discerned first - GPS antenna being one - is it there already or will I need to add one... any clues?

It certainly seems as if I can just add the DVD player/nav unit and plug the connectors as we have described throughout this thread... But am i missing anything else? The wiring diagrams certainly don't show anything.

Do you know what kind of plug the GPS antenna uses to connect to the nav unit? If it's one of the standards, then I'm sure I could use virtually any run of the mill passive (or active, probably) GPS antenna... i have several lying around - used to work on GPS systems for military.

 

The new amplifier solved the problem and now all audio is working perfectly!!! Yippppeeeeeeeeee!!!!

Now that my system is working again, my next project will be to add that Aux-In feature... I'm sure I'll have more questions along the way...

Thanks to all--especially QuadManiac--for all the insights and quick replies. I am truly happy--this moment was a long time in the making!

Regards,
Jon

 

Congratulations... now don't be a stranger, just cuz it works!!

 

@QuadManiac:

Don't worry--you won't get rid of me that easily! I'll be around here--undoubtedly with other issues that I need help solving as well as trying to help others whenever I can.

A few more details regarding this thread:

Before removing the amp, I recorded how the Nav audio sounded over the "white noise". In the sample attached, a clear (local) FM radio station was playing before it degraded to that noise (remember, the same thing was happening with a CD or Tape)--and then you will hear the Nav audio appear over the static. It's not a great recording but I can tell you that when you're in the vehicle, the Nav audio is truly perfect even though the static is there--uninterrupted.

The second audio file is just the Nav voice. You will hear that it's very natural. If you want more samples or a better-quality recording, just let me know and I will try to post it.

I will continue to follow this thread as well as other threads on this board. You guys are like a new family for me.

Let me know if I can help you with your Nav setup. If you look at the photos I had posted in a recent message in this thread, you can see the back of the Nav system, and the antenna attaches there. That connection image might give you an idea of how "standard" the GPS antenna input is... I will do a quick check tomorrow to see if I can follow this wire to the antenna itself.

Regards,
Jon

 

I see that the attachments didn't make it. The limit for .Zip files here is 97.7 KB, which is sort of, well, way too small. I therefore can't post my Nav/White-Noise sample with that limit unless I break the .Zip into multiple parts (it would take 10 parts to send the 12-second clip). So unless someone has a suggestion, I can't easily share the file.

So, I found that I could post only the Nav-voice sample, and I had to Zip it because this board doesn't allow MP3-format files to be uploaded...

Regards,
Jon

 

Thanks... and I do like that voice.

 

great thread...i am having a very similar problem...but it only happens with my cellphone input...occasionally, without rhym or reason the volume drops way down...it is very random...i've replaced the head unit and it didn't solve it, so now i am on to the amp...i didn't think it was the amp as the cellphone input goes directly into the headunit...oh well, i am assuming after reading this great thread that the amp must be causing some issue...this all started when my mechanic last did some work on my car and didn't disconnect my battery? at least it started a few hours after i left the shop so i am assuming it was that...so again...similar issue...my cellphone volume just drops without reason at random times, and yes, i've already replaced the factory cellphone with the Motorola bluetooth t605 that everyone uses...the problem was happening before i switched the factory cellphone and after...at first i thought it was the factory cellphone, so i replaced that, then the head unit, so i replaced that, now it must be the amp, which i need to locate somewhere...

 

Sorry to respond so late, but I only just came across this thread.

The Nav commands are sent from the HU via an ACP Bus which uses the yellow connector on the back of the HU. No Nav commands are sent via Ai-Net. Telephone commands are also sent on the ACP bus.

I can also confirm that the requirement to enter a code on these HU's can be turned off. The HU I have been experimenting with, which came from the USA, did require a code, it now does not.

I am not sure how I turned it off, but suspect it was while I was looking for adiagnostic mode in the HU by turning it on with various buttons depressed, never did find the diagonistic mode, but after that noticed it no longer required a code. About the same time I was also sending various commands to the HU via the AiNet bus to see how the HU responded, it may have been one of these commands but I doubt it.
One day when I get time I will try and set it back on.