2002 C320 Radio Sound Problem - PeachParts Mercedes-Benz Forum

MarekW · #1 07-29-2004, 03:34 AM

What could be the problem?

The radio is on (factory) , I can change stations and so on but no sound from any speakers.

Please help

SCLJA · #2 07-30-2004, 10:16 AM

The fiber optics could be unplugged. Did you do any work to the car , when did it start happening?

Scott

MarekW · #3 07-30-2004, 11:39 AM

The radio speakers did not work since I purchased the car, the car had a front demage from accident when I purchased it.

I removed the radio and also the amp from the trunk to check fiberoptic connections and everything looks good.

SCLJA · #4 08-01-2004, 09:44 PM

Check the power at the amplifier to se if it has constant power should be one of the two largest wires (red).

Gilly · #5 08-01-2004, 09:59 PM

Did any equipment get changed from original, particularly the radio itself?
Has any equipment been added, such as a cd changer or phone?
You could also unplug a piece of accesory equipment, or the amp, from the fiber optic ring, and have someone switch on the radio while you observe the end of the fiber optics cable and see if one of the cables blinks red, this means the radio is trying to establish ring lock, so at least the radio is trying to work.
Are you ever seeing a message in the radio that says something like "PROG"?

Gilly

MarekW · #6 08-04-2004, 12:17 AM

When I disconnect the plug with 2 wires from the amp the red light is blinking when the radio is turned on . I far as I know there was no phone or cd player attached to the car.
Never see the wording PROG, there is extra 2 wires with a plug at the end in the glove compartment that also blinks when the radio is turned on.
What could be my next step, where and how to check?

Thank you

Gilly · #7 08-04-2004, 08:25 AM

I see your problem now. The connector in the glovebox that's blinking is supposed to be attached to the CD changer, which evidently is missing. There is nothing there to take the signal and repeat it back onto the D2B line, so you are not achieving ring-lock and therefor your system is dead. You can either remove the radio and reconfigure the D2B line to take out the CD player, or as a cheat you could try to buy a D2B butt connector and configure out the CD changer that way, but in either case you'd need to have the internal coding in the radio changed to reflect the deletion of the CD player. Or at least you "should" need to do this, it may actually achieve ring-lock without changing the version coding, but I wouldn't trust the system to work reliably.
OH one other option would be to install the CD changer again. I assume there is also a small 3 wire electrical connector in the glovebox also, this also plugs into the changer.
Gilly

MarekW · #8 08-04-2004, 08:39 AM

Yes there is a small 3 wire electrical connector in the glovebox.

Can I do the recoding of the radio myself or do I need to go back to the dealer?

Thank you

Gilly · #9 08-04-2004, 08:52 AM

Well, I hate to say a dealer "needs" to do it, but you at least need someone who can access the radio "electronically" to set the version coding, this is done with a computer such as the dealers shop computer "SDS", so the dealer can do it for sure, there may be independents with SDS or another type of computer that I am not aware of which will do this.
The main thing is to determine which path you want to take.
With the last option I listed, (install a CD changer) this should simply plug in again (along with one screw which retains the bracket) and you have both avoided the dealer to do anything to the radio, and then the car will have a CD changer again, a nice option. Make sure you order the bracket too, assuming it's missing. You sometimes see these on eBay.
OK, the first option is the easiest, you can disassemble the connector with the 2 fiber optics cables, then there is a connector you can buy which will "butt" the 2 cables back together, which will complete the D2B loop. This alone "should" make the system work, although with the warning that it may not work reliably, ie it may cause a problem. NOT a serious problem, just the stereo may stop working for no apparent reason.
The third option is probably better if you're sure you don't want the CDchanger; that is to remove the radio, which is pretty involved, and put all the fiber optic cables back to the way they were before the CD Changer was installed, and also you'd need to do the computer thing on this option as well. The only way around the computer thing is to install the changer, this is assuming someone actually set the radio up correctly to begin with, i can't guarantee they did, just that the "should" have.
If you want to do "the quick and dirty" and use a D2B "butt" connector, I think I may have at least one laying around, no idea what the part number is though, you'd probably need to order one.
You have to handle these fiber optic cables very carefully, they can't be kinked or bent at too far of an angle or you'll ruin them and you can then end up with these problems again!
Gilly

MarekW · #10 08-04-2004, 09:00 AM

Great, thanks for quick reply.

I will probably start with the butt connector and try to look for the cd changer, does it have to be original mb changer or can in be replaced with any other one?

Thank you

Gilly · #11 08-04-2004, 09:07 AM

Let me know how you make out finding the butt connector.

Hopefully Scot or Cleeve can help with both of these questions as far as a part number for a butt connector, and on the CD Changer question. My experience is with the factory stuff, maybe they know what changers will work, but it does have to use the fiber optics system, unless you went FM modulated or something, but that won't fix your problem if you did that, it'll still be dead.

Gilly