: '92 Eldo bose Gold, symptoms, help diagnose please



The Gold
04-03-12, 11:22 PM
Hello, I have done the due diligence btw two forums and also read the FSM for trouble shooting but all that is inconclusive. Bose Gold '92 Eldo Touring
I am hoping one of you audio smarts can point to narrower possibilities and quick tests.

Symptoms, front passenger door speaker began to emit pop sound rarely. Within a couple of days it emitted that static pop sound and then sound like a trumpet or angry hornet. All sounds very loud but controlled by volume control.
The noise would emit from radio or cassette (CD is broken). Otherwise all functions were ok and everything worked and sounded correct. Soon after, the same day, that speaker would emit a blast of air-like sound. Repetitive. I turned radio off to avoid damages.
Upon turning it back on after a few minutes, I'd get the staticy pop noises after a minute or two.
I swapped out mini fuses for RAD(ign) and RAD (bat). Upon reinstalling the RAD (bat) minifuse I saw a spark jump on one end of the fuse terminal as I pushed it in. ( a second time on another day with another minifuse, the spark did not occur.)
Afterward I noticed that the clock was not on with battery power and the radio would not come on with battery power. I turned on the ignition aux. and the clock went on (but lost memory) and the radio worked but had the static-pop noise on same door passenger side speaker.
I turned off the ignition and the clock remained on and I was able to turn the radio on and off with battery power. Then soon after I was not able to do that and the clock went off.
All would only work with the key in aux. or engine on. Noise persisted. At this point only in that one speaker, but now the static appeared also when I turned the vol. knob on and off.

FSM had me remove the C2 white harness speaker connectors from the radio receiver in the trunk. Tested the radio. Clock still off and not working on battery power. In ignition aux. clock went on (lost memory) and radio worked but static pop noise still present in onset speaker but now seemed to emanate from front dash also. I was not aware of speakers there or else it was an audio illusion or maybe the left speaker kicked in and I heard the stereo sweet spot in the middle or it was the effect of the C2 harness removed....(no noise from rear speakers)

The algorithm of the Chart 14 "bose speakers noisy" goes on to try to isolate a noisy speaker etc. If I am to believe this diagnostic chart, the remote radio receiver is OK. BUT that chrt does not take into consideration the new series of symptoms: no battery operation for clock and radio.

There is no whining noise nor any noise associated with the car's operation or velocity of engine RPM.

My battery ground and pos. cable is fine. Antenna motor works fine.

p.s. what does the FSM mean by "Back out audio wires at noisy speaker" ??

also is there any way to disconnect an isolated speaker with out removing the door panel and getting at the speaker?? i.e. from the trunk modules?

How does one "inspect for shorts to ground or battery" ?


Well, I hope somebody with experience has seen this combination of symptoms and can help me narrow down some test points etc.

I pulled the mini fuses now to avoid a battery drain or battery power damage to the audio units, just in case, or any other trouble. The battery was not draining before and not presently. It is just a precaution.

THANK YOU

cadillac kevin
04-04-12, 12:22 AM
I'd say you blew the fuse for radio memory by swapping them around with the battery hooked up.
also, the various noises you described as coming from the speakers are symptomatic of amp failure.

creeker
04-04-12, 01:31 AM
I'm on my 2nd. 92 eldo. and had to replace sound systems in both of them, they just plain wear out, dont try to adapt to bose with other stuff, I've been
there twice and the best solution is to replace complete system with after market unit.

aeronca36606
04-04-12, 01:52 AM
Capacitors dry out in the amps causing the symptoms you describe. If you are handy with a soldering iron they can be fixed on the cheap. You can also get replacement amps although at a price. The amps are easy to change. An aftermarket system may be a cheaper solution but remember you will need to change everything. The bose speakers are only 1 ohm impedence and this will blow out most of the aftermarket systems amps.

I also do not like that there are almost no radios available that fit the dash correctly. Almost every installation i have seen looks rag tag.

I like to stay with stock when i can, (Unless you are looking for a super system).

Jesda
04-04-12, 11:30 AM
You can install amps from a later Eldorado or Seville.

I replaced my 92 Seville's Bose Gold HU with one from a '94 but had to give up tuner and power antenna functionality. The sound quality was greatly improved.


You can call Bose for a quote or you can try carstereohelp.com or any number of shops that do repairs on these amps.

The Gold
04-05-12, 03:01 PM
Hello All, thanks for your opinions and insights. After dpoing my research prior to posting, I was aware that amp failure on a particular speaker can cause popping noise.

I rechecked the minifuse to the Radio (Bat) and that battery operation fuse point seems OK. I replaced the fuse and this time no spark was seen. Each time that I had pulled and reinstalled that radio-battery fuse, the radio HU was powered off.

I don't see how not disconnecting the car battery for minifuse replacement can create a problem. The owner's manual and FSM don't mention the need to do this. No other car I have owned required battery disconnection before removing and reinstalling a radio or other fuse.

My knee jerk conclusion is that the amp on that passenger side door speaker is out. And like one person said, the capacitor certainly looks like one can replace on one's own. Or try the luck at a junk yard. But I want to avoid removing the door panel because usually that leads to broken retaining clips etc.

BUT, since it also is combined with the problem of not having battery power, I am wondering whether this combination of symptoms points to a particular part of the system other than a speaker amp.

Rather than go fishing with tests, I'm trying to ask the forum for any specifics.

p.s. what does the Factory Service Manual mean by "Back out audio wires at noisy speaker" ??

also is there any way to disconnect an isolated speaker with out removing the door panel and getting at the speaker?? i.e. from the trunk modules? The c2 harness I already disconnected according to the FSM did something for a test but the speaker sound was still present.

How does one "inspect for shorts to ground or battery" ?

Thanks for everybody's input so far !! Please continue.

The Gold
04-05-12, 08:23 PM
Found this for what its worth for others' reference

Stereo wiring for 1992 Cadillac Eldorado?
For 1992 Cadillac Eldorado check this Car Radio Wiring Schematic:

Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger Wire: Pink
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size:5 1/4/ speakers.
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Rear Speakers Size:6/x9/ speakers
Car Audio Rear Speakers Location: Rear Deck
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

The Gold
04-09-12, 07:32 PM
OK here is an update.

I stumbled upon a feature I was not aware of nor was it mentioned in any manual or FSM.

Apparently the radio's clock digital display will shut off after about 5-9 minutes of turning off the ignition assuming one does not open a door.

If the radio is on while you shut off the ignition it will likewise remain on and allow you to turn it on and off on battery for up to 5-9 minutes after the ignition was shut off and having NO doors opened.

If the radio has remained on after ignition shut off and one opens a door, the radio and digital display of clock automatically shuts off.

Apparently these are convenience features thAT i WAS NOT AWARE OF SINCE I'D TURN OFF RADIO BEFORE PARKING CAR.

So that leads me to be more comfortable with the idea that it is the passenger side speaker amp that is in need of new capacitors.

Live and learn..not everything is in the manuals.:)

aeronca36606
04-18-12, 12:15 PM
That feature is called Retained accessory Power. It should also allow you to use your power windows during that same 10 min period.

You should pop over to some of the Corvette forums as they have a lot of info on the Amp repair. Some of the 80's and 90's Corvette use the same type of Bose System.

Be careful when switching amps with other models of cars. These Amps and Speaker assemblies are tuned to the Cars acoustics. (Though you would have to be pretty critical to hear the differences as long as the Amps are replaced in pairs).

If you do a little searching you can find Capacitor Kits available with all of the necessary parts to do the repairs. Even if you only see one cap bad, Replace them all.

The Gold
04-19-12, 04:00 PM
Thanks aeroca36606, it is a good idea to replace all capacitors. I don't look forward to dealing with the door panel removal. I have several reference links on how to do this correctly but I know from experience that the physical situation always has surprises. Those dumb plastic hooks...

I'll probably go to a junk yard and look for a guinea pig first..

The Gold
11-03-12, 01:24 AM
Update, I had the speaker amp rebuilt by car stereo repairs inc.

I just decided it would take me longer fiddling with the iron and bad eyes and busy schedule to do it myself.

It was worth the price.

I just installed it and it sounds great.

Door panel removal and re-installation was not bad at all.

I did go to a pick n' pull months ago and removed an Eldo door panel etc. for practice and notes.

so thanks to you all for pointing to the bad capacitors !!

N*Caddy
11-07-12, 09:32 AM
Never go after fuses if you have bad sound. You have some sound it means you have power.
The electrolytic capacitors are supposed to last ~10 years, after that you are on borrowed luck.
When you replace the electrolytic capacitors ALWAYS replace with the same (or maybe greater capacity, but NEVER less) and the HIGEST rated voltage you can possibly find. If the original capacitors are rated say 25V go with 50V rated capacitors (or higher).
The greater the voltage rating the bigger the capacitor (size wise). As long as you have space on the PCB for it go with the largest one you can fit. A capacitor with a higher voltage rating than required for the application will last longer.