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2001 El Dorado
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Discussion Starter #1 (Edited)
I just purchased a 2001 El Dorado and am in the process of fixing the array of minor problems that it has. Just fixed the turn signal switch which was jammed against the clock spring cord and replaced the flasher relay.

I'm moving on to the radio now, it has the Bose system (no CD changer). The head unit functions, all the features seem to work, but I'm not getting any sound from any of the speakers. I've looked at the schematics for the radio system and it looks like I have four speakers with individual amps, a radio interface module, Bose relays, head unit, and power antenna.

I'm figuring that I have an issue with the audio signal making it to the speakers, but I suppose there could also be an issue with the head unit not sending a signal despite the fact that the display tells me that it is tuning etc... I've heard that it's a bad idea to disconnect the head unit due to its integration with the security system; how do I go about diagnosing the problem?

BTW: Checked fuses already...
 

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1997 Cadillac STS (BOSE w/AUX In, Massage Seats, URPAS, "Z")
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If the radio works (as in has display, responds to all commands) but no sound then:
1. I would check the 30A AMP fuse (trunk fuse cluster)
2. I would check the two BOSE relays if functional (trunk relay cluster)
3. I would check G400 and G401 grounds, the two ground connections found directly under the rear seat (one left one right).
4. I would check the RIM if receives power on pin B1 (C2 connector) – it should as is sharing the same fuse with the HU the 10A Radio/Phone Fuse (trunk fuse cluster)
5. Check the RIM pin D2 on C2 connector if it has power (is the relays command or AMP on).
6. I would check the codes looking for U and IRC codes mainly.
7. It will be a good idea if a CD changer will be present, you can test if it works on CD changer, if it does then the RIM is good, it doesn’t then chances are the HU is good but there is a issue with the RIM/Amplifiers (refer to 1 to 5 above).

I know you mentioned the fuses were checked but make triple sure the AMP fuse is good and in place (and actually measure to see it has power on both ends). Then disconnect one of the wires connected the rear shelf mounted speakers (the easiest accessible) and measure if you have battery power between the BK and the OG wires while the stereo should work. If no power then go after the BOSE relays/RIM.
If power present then go after the audio wires between HU and RIM. By the way you can tell if the speakers are on by simply putting your ear near the speaker and listen for a faint fsss.
You can disconnect at will the HU, nothing will happen as long as you install it in the same car (if different car you need to clear the VIN first).

Here is the part where you should concentrate first:

For even more information refer to my thread.
 

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2001 El Dorado
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Discussion Starter #3 (Edited)
I'm getting power to the 30A fuse and both relays, but I'm not getting any power at the orange wire in the C2 on the RIM. Any ideas??
 

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2001 El Dorado
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Discussion Starter #4
I also discovered that I am getting signal off of B5 and B7 on the C1 connector; Left and Right Front Low Level Audio Signal. But I don't seem to be geeting anything from A3 and A6 (Right and Left Rear Low Level Audio Signal). I am getting power on C1 at B1 which is Positive Battery Voltage.

I'm not sure whats going on...
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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according to the schematic, check the rear compartment COMFORT 10A FUSE
 

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2001 El Dorado
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Discussion Starter #7
Low power wire for the relays is supplied by the RIM, right? So my RIM isn't activating the relays which means no power to the amps on the speakers. My Radio Interface Module is probably bad huh?
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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unfortunately, I've seen those things for sale on ebay quite often. you could say the proof is in the pudding so to speak. Yet, I'm baffled to as why would it go bad?
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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now, just because we're getting voltage, doesn't mean you may not have a bad ground or disconnected ground somewhere. You need voltage and a good ground to complete a circuit. start checking for loose grounds or corroded ground wires
 

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2001 El Dorado
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Discussion Starter #13
now, just because we're getting voltage, doesn't mean you may not have a bad ground or disconnected ground somewhere. You need voltage and a good ground to complete a circuit. start checking for loose grounds or corroded ground wires
I have the back seat removed and it looks like the three ground are solid (G400-403, I think).

That 10amp Radio/Phone fuse is good too.

Wish there was a way to test the RIM.
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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all the speakers (assumming you have UQ4) are grounded via a black wire where they are all spliced together at splice junction s329 which then goes to ground g400. (s329 In the body harness approximately 6.5 cm/2.56 inches from the right seat pan channel) g400 (In the left rear of the passenger compartment, under rear seat). check the grounds for cleaniness and good contact
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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the radio and rim are grounded together at splice s407?! you have to check that one also....s407 then grounds to g400. S407 (In the body harness, approximately 77.5cm/30.51 inches into the cross car break out. If you have the factory service manual it's in page 8-415
 

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98 eldo/KD54 w/N37,T96,QA1,D55,DS3,U1Z. U3R next
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I believe you have a bad ground. check splice s402. It grounds the bose relays at connector c307. s402 grounds to g401

s402 (in body harness approx 29 cm/11.41 inches into croos car breakout) That's the harness that runs across the car when the rear seat is removed.

c307 (body harness to body harness, tapped in the body harness approx 15 cm/5.9 inchesfrom the cross car breakout.)

I hope this helps. Right now i believe your issues are right there in the cross car harness.
 

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2001 El Dorado
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Discussion Starter #17
the radio and rim are grounded together at splice s407?! you have to check that one also....s407 then grounds to g400. S407 (In the body harness, approximately 77.5cm/30.51 inches into the cross car break out. If you have the factory service manual it's in page 8-415
I'm working with this online manual (alldata), but it has the splice and ground locations. I'll check that out tomorrow morning.
 

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good luck, if all else fails, you'll be hunting for a RIM, but let that be the last option........
 

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1997 Cadillac STS (BOSE w/AUX In, Massage Seats, URPAS, "Z")
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Why you are completely ignoring the schematic I posted for you.
If your radio works then don’t bother with the Radio or Comfort fuse.
I mentioned clearly to check if you have voltage to ANY of the speakers (even suggested witch one is the easiest accesible).
You don’t have voltage check if is a ground fault (as in check continuity between black wire and ANY exposed metal on the car body). If is not a ground fault then move upstream to the relays. Do you have power from the AMP fuse to the relay (again follow my schematic, tells you witch pins are what, just pay attention to the schematics!).
You should not ask witch wire supplies low voltage to the relays (actually is the same voltage just low current), is very obvious in the schematic and my post (see point 5) is connector C2 pin D2.
You have voltage on this wire then check your ground (see is coming from G401 thro S402 all under the rear seat on that harness plastic wrapper).
You have both control voltage and ground but the relays don’t work then change both relays (highly unlikely for both relays to go bad at once but hey…you are the lucky one)
You don’t have power on the relay control wire from the RIM (again pin D2 connector C2) then check if your RIM receives power.
The RIM is powered from the same Radio fuse to pin B1 connector C1.
If the power there then is the RIM grounded on pin A1 connector C1?
If the RIM has both power and ground then you SHOULD have power on pin D2 connector C2 (the relay control) even with no data wire connected (trust me I know).
If you have no power to this pin then look for a new RIM.
Here is the other diagram you may need.


Only if the power to the RIM is there, the power to the relay control wire is also there and the data wires are connected correctly (to the CVRSS module one and RFA module the other) then and only then I would be looking for the audio wires between HU and RIM. You can use regular headphones (I assume you don’t have a fancy Oscilloscope) to test for audio signal.
As you can see there are 2 audio lines from HU to RIM, one stereo (the actual sound) and one mono the Chimes. Is so unlikely for BOTH to go wrong in the same time sooooooo unlikely.
Your problem is 99.999995% located in the electronics bay or the 2 grounds under the rear seat (G400 and G401) and the wiring between.

Do you know how to read the schematic? If you don’t do not be embarrassed to ask, is not a big deal, I don’t know how to write poetry either…I am not ashamed to admit.
 

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2001 El Dorado
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Discussion Starter #20
Do you know how to read the schematic? If you don’t do not be embarrassed to ask, is not a big deal, I don’t know how to write poetry either…I am not ashamed to admit.
Thanks, I'll check all these things today. I do know how to read a schematic, good sir; but my understanding of electronics is basic.
 
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