I've been looking to upgrade my anemic system by adding a Pioneer CDX-1277 RF-FM 12 disk changer and a simple amplified bass tube but wonder about potential problems.

1. Where is my antenna, cable, and can I conveniently access it? A convenient call to Crutchfield's techies told me that if the 99 C-230 used the same cable and connectors as the 98 ML-320, there would be no problem. Anyone know if they're the same?

2. Is there a good source of power for the CD-changer and say, a 150 watt amplified tube in the trunk? Do I have to run a wire from the dash?

3. Can I grab audio feed from the rear speakers for the sub, or must I remove the radio and splice into the audio output?

4. Would it be cheaper and easier to avoid the sub, and merely upgrade the existing speakers with premium speakers?

If at all possible, I'd like to avoid the need to run cables from the front of the car.

Any advice would be great!

Thanks,
Glenn

Hi, I'm a dealer guy, I may have some advice that will help. I don't believe the ML is similar to the C-class as far as the antenna. I believe your car still has a "regular" power antenna, the ML is a glass integrated antenna, the rear hatch glass. Check out behind the left trunk trim, the splitter is there, mounted to the antenna assembly. For power, you should be able to use the one for the factory pre-wired CD, this would avoid running a seperate wire. It would be good to get the wiring schematic for the factory radio, and CD changer. The wire for the CD changer is behind the right trunk trim. It is a 3 wire. One is power to run the CD changer (provided by the radio, ground (also provided by the radio) and a "wake-up" line from the radio, to get the factory CD changer to get on the D2B (fiber optic) ring.
Gilly

In my curiosity, I peeled away the left side trunk trim and actually managed to get it all back (never able to do that on any GM car).

On the left, I found a couple of interesting wires you might find familiar. First, a loop of around two feet of coaxial that runs down and disappears through a rubber grommet into the left corner (into the bumper antenna, no doubt). Oddly, at the end of the loop is a coaxial connector not really connected to anything at all. It's taped neatly to the frame as if waiting patiently for someone to use it for something.

Second, as part of a bundle of wires coming from the front, is a much smaller black coaxial wire around half the size of a regular "cable-TV" coax. It's threaded the same and all, but has a small white plastic tip. Again, it's just sitting there with its free end hanging loose.

Lastly, next to this small coax I found what looks to be the male end of a serial cable like I have between my PC and printer. It's wrapped nicely in foam and velcro. Given the proximity of the small coax and serial cable connectors over the left wheelwell, I assume they're meant to be used together.

Although I have no idea what the last two are for, I suspect the larger coax in the left rear bumper area is antenna. Still, why is it not connected? Is it meant, perhaps, for a cellular phone to join in? I always thought a cellphone would connect to the end found in the compartment between my front seats.

Have I found anything useful?

Thanks,
Glenn

Glenn: I'd have to research a little on what the 99 C-class had available, but yess, what you've found is the pre-wiring for the phone. I didn't think a 99 C-class had a bumper antenna, but if you follow the lead and it passes through the body in the area of the bumper, then that's what it is alright. The smaller coax I believe goes to the center console, it is the antenna wire that is used for the handset for the "portable" style phone, I believe a 99 used a Motorola Startac. The electrical connector with the data-cable style connector would connect to a "Y" cable that connected to telephone equipment, either a PSE for a portable phone or a TRU in the case of a mobile phone (if it was available in 99). Is there a fiber optic connection on the left? I know there is one on the right for the CD changer. I'm not 100% sure, but I don't think much of this would be of use. The 3 wire connector on the right side might be. I don't know if it will mess up the factory radio by trying to use these 3 wires or not. I would think you would be able to use the power and ground as a trigger signal to turn on the aftermarket equipment, but you may need to have a dealer reprogram the radio to show an installed cd changer, even though it is not there. It may work OK as is, though. I'm still curious, as I can't remember, this does have a "normal" power antenna, right?
Gilly

Thanks for the great advice. I would never have known where to look and would probably never dared! Anyway, thanks to digital, I snapped a couple images of what I saw.

This nicely padded control unit was tucked in the frame on the right rear, behind the wheel well:


Inside the padding were two loose connectors, one evidently a power supply consisting of three wires:


The other looks alot like the fiber optic connector shown at the Becker Audio site's installation page for Mercedes:


I'm grateful for your help and very impressed by the sharing of knowledge on this Mercedes community site. My thanks!

Glenn

That module inside the padded box is a mighty important part, young man. That is the PSE pump, stands for Pneumatic System Equipment (in German, I'm sure). It controls the unlocking/locking of the car, the anti-theft alarm, many exterior and all interior lighting features, it even has a built in crash sensor (not for airbag systems, though) to shut-off the fuel pump, unlock doors, and turn on hazard flashers in a crash. So if you come out from a store and your flashers are on, the doors are unlocked and the car won't start, better take a walk around the car to look for serious damage! (Actually, I think the car needs to be running to begin with). The harnesses are the ones I am talking about for the CD changer. Let me know if you need to know what the 3 wires are, the brown one is definitely the ground from the radio. I don't recall those wires being put into the spongey box for the PSE pump, though. But as you can imagine, it's been a couple years already since I put a CD changer in a 99 202 chassis. Time really flugens, eh?
Gilly