OK, I have a very odd audio system problem in my car. It seems that the mid/high speakers (dash and deck) do not function on the left side. They are working fine on the right.

The diver door sub/bass speaker *does* work though. Now... here is my dilema.

I've looked over the wiring diagrams on in the 300+ page PDF and found the pages for the '92 audio systems. I found two systems but the wiring on neither would explain what/how my system works. I could understand the operation of the door mounted bass if I had the 5 speaker (per side) system running off of the two amps (one for each side).

However I can only locate three speakers (dash, deck, door). I pulled the panels and I found the tuner module (that is interfaced with the head unit viat the 10-lead round cable) and two units that look like the amps for left and ride side (according to the wiring diagram).

If one of the amps was dead I'd understand no left side audio but I still have the bass. If I fade the head to full right the door base speaker quiets to near zero output. If I fade to full left I only have the door speaker working.

When I used the concole fader (fore/aft) to fade, on a left-rear there is no discernable audio (there is some channel bleed into the right side but basically no audio). Fade to left-front and I get just the door speaker.

Looking at the only diagram that shows the seperate amps left/right I should have 5 speakers (1 dash, 1 door and three drivers somewhere aft.. I'm not fiding them). Regardless.. the diagram indicates that the door/dash are driving off of similar output leads, so why is only the bass working?

This making no sense to me (and by now probably not making much sense to anyone reading this). I don't know what other methods I can use to try to narrow down the problem.

I'd like to get an IPOD installed at some point, and maybe it's the head unit that's not working right? If I have an aftermarket head installed, are there any that will play nice with the factory components in the rear (using line-out, with an adaptor to power the factory amps etc?) or will I need to re-wire the entire system, get more amps and some crossoves to make the door drivers and dash/deck drives work right?

HELP!

I used to do this for a living... but this system has my stumped...

If pictures of the parts are helpful to illustrate anything.. I can pull the panels again and take some pics.

PS. I have no clue what model Becker head unit this is but it does have the changer output, I know, I pulled the non-functional changer out, and pluged the head's cable right into the rear tuner/amp last week).

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I took a look at the system schematic and the only conclusion I can come to is that there is a channel out in the amplifier. Those two speakers are connected in parallel and the high speaker is coupled with a crossover cap. There is no way if one speaker was blown that the other one would not work. The chances of both speakers being bad at the same time is not likely. The fader is before the amplifier so it is not likely to be any part of the problem...The only thing that could be done is to disconnect the speakers from the amplifier and check each speaker (hi and mid) for correct impedence and see if it leads you anywhere. If the amp is blown in that channel it is likely that it failed because of some lower impedence in one or the other speaker of that channel. While you have it disconnected substitute another speaker in the circuit so as to test the amp. Would be interested in any outcome of this.....

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83 300CDTurbo 307,000
2005 Honda Element 266,000
56 Nash Ambassador Country Club Special 34,000(under restoration presently)

http://www.peachparts.com/shopforum/car-audio-multimedia/125099-123-install-extreme-dynamat.html

Thanks,

Those sound like good ideas. I'm about to get into 'work on cars' mode and start looking at the amps and wiring. It sounds like you read the same thing I did in the wiring.. it should all work or all fail... but.. the door mid-bass is what is tossing a wrench into my diagnostic tree... I'm just not comprehending the scenario that allow the current situation without possibly multipe unrelated failures.

Once I can figure out how to pull the rear speaker cover without wrecking my car (it's been a while.. I know how to do the front though, that I recall vividly) I'll see what's going on. I have a set of new and a set of old factory dash spreakers from another W124 that I should be able to plug in. I hope I have some spare speakers around here.. LOL.

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My radio does the same thing, except the problem is with the mid/high speaker on the right side! But it only happens occassionally. I pulled the speaker grill and the wires are absolutely fine...plus the right door speaker works all of the time. I think amp in the radio is going kaput and that the door speakers must be driven by another amp or something. Of course my car is a 95 model so the systems might be different...

I want to install a new radio, but I want to make sure it will power the front and rear speakers + the door speakers. I've searched this board and other places and it still isn't clear to me how to wire in the door speakers with a new head unit.

I have considered the same option but not sure I really want to rip out all that stuff, buy some more amps, try to find room for them, and then get the required wires up the the front (I've taken a few W124's apart in my time and it's no party once you reach the b-pillar)

UPDATE:
Removed the rear panels and started checking connections and the amps. By swapping the amps around I know the amp is not the issue. Right channel works normally off of either amp. And the side that is not fully working will power the bass speaker once the amp is unplugged. What surprised me was that the huge tuner in the back only has 4 wires heading out of it that look to be speaker signals. I'm back into the wiring diagram to see if I can make heads or tails of which wires are supposed to go where and if it's signal not getting into the amp or signal not getting out.

Fun stuff...

PS I'm taking pics of the parts in case anyone wants to see what they physically look like. You never know.. at least I can be relatively certain which of the systems I have.

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Yes, this is the same conclusion I came to. HOWEVER, so far I have found the left rear speaker cluster to be blown out. Pulled both rears and swapped them. Well the right rear cluster works on the left rear circuit. Sheesh.. I pulled all those electronics over a blown speaker?

Now.. to check the fronts. I just find it very odd that both the left mid/high drivers would be out. Maybe the connection is broken on the front??

At least I did ID the system I have and it is a 5-driver system with a cluster of three speakers in the rear. 1 mid/bass and two very small companions. One of them is likely the cause of the cooked rear (the impeadance was nearly infinate when I tested the wires.. this was my first clue something was hosed up in the drivers).

Once I swap the front drivers I'll know for sure how many speakers I need to go and track down tomorrow. At least this looks like an easy fix. As horrible as this might sound to some, other than the IPOD issue I like the stock system! 5 years of pro-audio work and a nasty shooting accident has left me hearing damaged so.. my opinon of audiophile sound is highly suspect at best.

UPDATE: Well, an hour or so later I have my conclusion. Left speakers blown. Swapped fronts and viola.. left channel works fine. So, a new set of speakers are in order. No biggie, they are 13 years old as is. Wondering what I can bolt into the rear though. That stock part's mounting is radically different than your typical co-axial round driver mounting system. We'll see what the local shops can come up with in regards to speakers. I wonder why the left bass did not blow out too. In all the years I've worked on audio this is the first time I recall two speakers on the same channel were both totally dead. Not just blown-out but dead.. DOA.. no sound at all, yet the other channel's speakers were clear. This car has presented a lot of firsts in it's first month of life with me. LOL

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Do the stock speakers blow from putting them loud or....?

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99 C43
98 S420
99 C230K
01 C240

Typically that would be the cause of a burnup. Too much power but everything is stock, so I'm not sure how it could have done that. Hopefully that amp does not freak out and smoke the new speakers.. installing those front ones always sucks..

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Yeah If I have it all stock, which I do, Im sure its safer for the speakers?

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99 C43
98 S420
99 C230K
01 C240

Although it is not likely to have 2 speakers blown it is possible. Glad to see that you actually diagnosed the system but not without some pain. Of what I know about why speakers blow it is possible that the amplifier at one time had DC on the output but I would be interested to know what the impedence of the blown speakers were. If they are open (no connection) it was probably caused by DC on the output. Also do the voice coils on the blown speakers move. If they do not move they definitely had some nasty signals to them. Typically OEM system amplifiers do not have some of the features of aftermarket amps such as protection circuits which would have eliminated this major malfunction. In my time I have seen some pretty wierd stuff happen to speakers when they are driven hard for long periods of time and then there is an amplifier burp and the little voice coils in the speakers get fried. I would be careful of buying new speakers and just hooking them up and thinking they are fine...If it happened once it may happen again...Does this system have the Activ Bass. If that is the case it has an amplifier mounted around the speaker and the signal getting to it is a already an amplified signal but is low and the small amp on the speaker itself jacks up the level.

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83 300CDTurbo 307,000
2005 Honda Element 266,000
56 Nash Ambassador Country Club Special 34,000(under restoration presently)

http://www.peachparts.com/shopforum/showthread.php?t=125099

Ah yes.. DC of any measurable amperage would really mess them up. In cases where I've seen big amps do this the voice coils are sort of welded to the magnet / body and they do nto move. These moved smoothly. Both showed a nearly wide-open circuit but not totally open. Which was weird.

At any rate.. it's been a couple of weeks, system is sounding good and the bass/mid/high balance is better than I had expected with the lower efficiency high/mid speakers.

What I am working on right now is completing the integration (if you can call it that) of an external audio source using and FM modulator but not the type they are selling that plugs into the cigarett lighter or any hokey stuff like that. I'm going old-school. It's hardwired into the antenna and disconnects the external antenna when in use. Problem is right now I have to physically throw a small switch to turn the unit on/off. I'm going to go looking for a device that will look for a signal on the audio line and trigger a relay to enable the device automagically.

This is the device I found one at a local audio shop. They were still pretty proud of it (pricey) but I figured I did not want to soure the net for one so I paid the $49.00 they wanted for it. Pfft. I can go without 2 latte's and make up the extra cost.. LOL

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Not sure if you are aware or not but Becker of North America can modify your head unit with a miniplug jack comming out of it for aux use. I think LaJolla does similar modifications but im not sure about this model which is BE1432.

Becker's mod requires you to have a tape in the unit to be able to get the audio through. As far as the miniplug jack, when there is a wire plugged into it the tape audio is then bypassed to give you the hard wired aux audio. They charge $100 for the mod.

I've read about it. I still might do it. So far the inline FM modulator is doing fine and I get plenty of volume out of the system. However, I'm getting some popping on the rear left channel (that amp used to be on the right where I had two blown speakers) so upgrading that system is likely just a dead-end for me.

Alpine is supposed to release a new head unit with a USB 2.0 interface that will control the iPOD at full speed unlike the current interfaces that have to load songs to get info which slows down the interface a bit. So the entire system might come out but I'm loath to get some blingy headunit installed in my car.

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Where did you find the wiring diagram? Moreover where were your amps located? I'd love to see the pictures of what they looked like as well. I was having problems of sound popping in and out for a week or so and then eventually everything went kaput. I'm a novice at car audio, but know a little. So what I did was remove the deck and bought a cheap sony cd deck. One with a little bit of power incase I had to bypass the amps. As I cut the wiring harness out and knew there was know kit I just put a 9volt battery to each of the speaker wires. If the speakers are good you can get a pop out of them and you know which wire is which. I have a 92 E class. The Door drivers both worked right and left. The in dash right channel worked but not the left. The rears both popped but sound only popped in and out. Now in my little experience I diagnosed the problem as an amp issue. My panel fader works. Currently I have sound but it is crappy. I'm thinking of trying to bypass the amp right now to get the rears working, but when my taxes come in I am getting four new 6 and three quarters with directional capability and just throwing them in the doors and wiring straight to the radio.

christopher.p.cox@gmail.com

If you get time send me what pictures you got.

I used a search engine (google) and typed in several combo's of words til I found it....

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83 300CDTurbo 307,000
2005 Honda Element 266,000
56 Nash Ambassador Country Club Special 34,000(under restoration presently)

http://www.peachparts.com/shopforum/showthread.php?t=125099