960 1996»«Audio/Amplifier/HeadUnit/Speakers

c0ncentricity · Post by **c0ncentricity** » 03 Aug 2009, 08:57

Hi everyone,

I have a bit of an audio problem with my 1996 960 Sedan.(had the same thing with a '97 version but not quite as accentuated)

It appears the audio on the passenger side is not as loud as the volume on the driver's side and I am not sure what's causing it. I used the balance on the head unit/radio and there is a NOTICEABLE difference. It seems it doesn't matter if I use the radio or the tape - the sound difference between driver's side and pass. side remains.

Has anyone encountered this in their Volvos? I am thinking it might be an amplifier problem? Where is the radio amplifier and how do I remove it? If it's head unit problem has anyone ever discovered a way to repair it?

Does anyone have a clue as to where to start? I'd rather not replace the stereo - I think these radios are plenty for me - but I would like to hear the stereo sound at about the same level.

Thanks in advance to you all for taking the time with my message.
Paul

Post by **billofdurham** » 04 Aug 2009, 15:46

Welcome to Matthew's Volvo Site.

I haven't had this problem in my Volvos but I have had it in other radios. The first thing I did was to spray the works of the switches with a switch cleaner. It made a noticeable difference.

Some of the 960s had an amplifier and some didn't. If you have one it should be mounted near to the head unit. There will be a DIN cable from the back of the radio to the amplifier. Follow this and see where it leads.

Bill.

c0ncentricity · Post by **c0ncentricity** » 05 Aug 2009, 08:03

Hi Bill,

Thanks for your help.
When you say "...spray the works of the switches...." do you mean the balance/volume knob?
Or are there other switches that I am overlooking that you may have had success with?

I am going to try to trace the amplifier, just like you said, by following the DIN cable (if applicable). What about the rest of the wires?! there seem to be 2 harnesses behind the radio - should I worry about those when tracking down the amp?

Thanks again for your time
Paul

Post by **billofdurham** » 05 Aug 2009, 11:45

spray the works of the switches

I put it this way because I have done more than one radio but it is usually the volume control/balance that causes the trouble.

There should be two plugs on the back of the radio whether or not there is an amplifier. The DIN lead is separate, usually with a round plug and thicker than the normal wires.

Bill.

c0ncentricity · Post by **c0ncentricity** » 05 Aug 2009, 14:10

Bill,

I did what you suggested. Doesn't seem to want to help any.
I bought a $10 can of electronic cleaner, took the radio out, removed the volume switch and sprayed it while rotating it from side to side. I blew it dry, plugged it back in and the results were unchanged.

However, I did notice that the back of the radio has an "AMP" connector that doesn't have a DIN cable attached to it. The DIN cable that is attached to the radio is connected to the adjacent port for the CD changer.

So am I safe to assume that there is no amplifier in my car, then? The problem lies within the head unit itself?

I also sprayed the back of the radio where the 2 harnesses connect (power, speakers, etc) but that doesn't seem affect the results either.

Do you know if there are crossovers that may or may not affect the transfer of sound to speakers? (Maybe they are damaged). I have a thousand questions but I don't want to burden you with them - you've already been kind enough.

Thanks again
Paul

Post by **billofdurham** » 05 Aug 2009, 15:31

The DIN cable that is attached to the radio is connected to the adjacent port for the CD changer

Do you have a CD changer? You only mention radio and tape in your first post.

Looking at the wiring diagrams the radio with amp services 6 of the speakers from the amp and the other 2, left and right side instrument panel from the radio. Without the amp all speakers are serviced by the radio. The 6 main speakers are wired to the smaller 9 pin plug and the left and right side instrument panel speakers to the larger 13 pin plug. Are all of the speakers on the passenger side working?

Bill.

c0ncentricity · Post by **c0ncentricity** » 06 Aug 2009, 08:29

No, no CD changer (that I know of), but the cable is plugged into the back of the radio. But there is a CD player on top of the tape player, so in opther words it's AM/FM/Tape/CD (model SC-815 I think).

Do you have a radio wiring diagram for this model? Can you share it?

The speakers on passenger's side are working to a degree, but, I will take a listen again to figure out which (if any) aren't working at all. It just seems that the entire passenger side doesn't have the power that the driver's side speakers have.

If I turn the volume all the way up it's maybe 30-35% of the volume on the driver's side, and the sound is flat (no bass, mediocre midrange and weak highs).

Any thoughts?!?!
Paul

Post by **billofdurham** » 06 Aug 2009, 12:49

I have two wiring diagrams, with amp and without. However, the model is not specified but usually the diagrams are one size fits all for a specific model/year.

Looking at the specs for the '96 960 it was fitted with an AM/FM Premium Sound full logic cassette stereo with anti-theft coding, amplifier, power antenna, CD capability and 8 speakers. This was the SC710. The limited version of the owner's manual that I have does not mention the SC815 until the '97 model but, as I said, my manual is limited and the SC815 could have been fitted earlier.

960 radio with amp.pdf: (1.01 MiB) Downloaded 416 times

960 radio without amp.pdf: (1 MiB) Downloaded 284 times

Looking at other documents for the 960 audio system it would appear that the CD changer, if fitted, was under the rear window parcel shelf. It was there on my 940 as a factory fit. Apparently some of the cars that weren't fitted with the changer had the lead fitted to save taking half the car apart later. It may pay to check to see if the lead is under the parcel shelf. With the SC815 unit with its single CD slot it was still possible to run the CD changer.

The amplifier, if fitted, would be to the rear and slightly left of the head unit.

With the symptoms you give I would suspect there is a breakdown inside the head unit which affects the passenger side only. It is not uncommon in any make of car.

Bill.

c0ncentricity · Post by **c0ncentricity** » 06 Aug 2009, 14:33

Thanks a bunch for the diagrams. Appreciated. It's rather difficult to read the text but other than that they seem to be accurate. What book did you get them from? I'd like to maybe get my hands on a repair manual I just can't seem to find one at the publisher I bought other repair manuals from.

You are correct, the radio I currently have in the car is from a '97, but even so, the '96 model had the same exact symptom which lead me to believe it was the amplifier. (Sorry if I'm confusing) - since however there isn't a cable running from the radio AMP connector I don't think there is an external amplifier.

I automatically assumed there was an amplifier but I fear, just like you suspect, that there is a break down in the head unit.
I'm going to try to investigate further, but I do appreciate all the time and effort you've put into the troubleshooting.

Thank you Bill
Paul

Post by **billofdurham** » 06 Aug 2009, 15:32

The diagrams are from a Volvo publication given to me by a former Volvo tech. It covers all models from 1983 to 1999 and is handy for the vehicles in which I take a greater interest i.e. real Volvos and not Ford look-alikes.

When I had my 960 I couldn't find a manual and Haynes, who also publish Chiltons, still haven't produced one. Their reasoning was "not too many of those about to warrant the expense of a full strip down and people who can afford to buy them will be having the work done by the dealer." That was part of the reply when I wrote to Haynes about the lack of a manual.

As you have most , if not all, of the speakers working it indicates that there is no amplifier.

Bill.