Speaker Wiring in C280 '98 - PeachParts Mercedes-Benz Forum

pmerriman · #1 11-05-2011, 07:31 PM

I have almost successfully installed a new radio/CD player in my Son's 1998 C280. However, I can't get the speakers to cooperate. I know the radio is putting out sound (wired a spare speaker to radio output wires and got music), however, something seems to be muting the car speakers. There are extra wires from the old factory radio that I can't identify their purpose. The factory radio must have had a built in phone or something in order to have these extra wires. I've read something here about faders and extra wires from those? I tried touching a 9v battery to many of these "extra wires" including the ones I'm pretty sure are the real speaker wires but I don't get any sound at all. I just think something is muting all the speakers at once. Help! My Son is tired of riding around college with a brand new radio sticking out that won't play!

RANDY P · #2 11-05-2011, 07:36 PM

there's a factory amp. Did you plug the amp remote on / antenna on wire to the appropriate one in the harness?

You can go speaker level into it and it works fine.

Do that.

pmerriman · #3 11-05-2011, 10:06 PM

Randy,
Thanks for your reply. Where is the factory amp located in the car?
Do I need to use the factory amp if my aftermarket radio has amp built in?
Is there a wiring diagram anywhere for the amp wiring? (been searching online)
Are you suggesting the factory amp needs power...maybe from the switched accessory wire?

My C230 didn't have an amp so the wiring to the new radio was quite easy.
Paul

RANDY P · #4 11-05-2011, 10:19 PM

It should be on the LH side of the trunk behind the panel.

I would use the factory amp, makes life a hell of a lot easier instead of chopping up the wiring in the car. The factory amp gets it's "ON" signal from +12 V in the harness for the radio. I don't remember the color of the wire but it's there.

Hopefully you used the METRA wire interface harness- if you did, simply connect the amp on or antenna on lead to the same labeled wire in the harness.

I have an Alpine HU going to the factory amp in my car and an aftermarket sub powered off an Kenwood sub amp. Works great.

rjp

pmerriman · #5 11-05-2011, 11:34 PM

Randy,

No, I didn't use a METRA harness since my own C230 radio change out went so easily without one.

Any idea how I can identify this power wire for the amp? As I recall, it may be the same color combo as the power wire for the radio. I'll check it tomorrow. Noticed a yellow wire with black stripe that was inside a black plastic tube all by itself. Any ideas on function for that wire?

I think we are making progress here. Will give it another go tomorrow.

RANDY P · #6 11-06-2011, 02:44 AM

I don't remember it being isolated in it's own sleeve, then again there could be a difference between the two.

frankly, it's a process of elimination. If the other wires are all taken that must be the one. I would imagine the AM reception is nonexistent at the moment as well?

IIRC the power antenna and the amp feed off the same turn on circuit.

Try this link- it should be blue / white- on my car i'm pretty sure mine is. This is for an E class but should be the same.

1998 Mercedes E-Class Stereo Wiring Information

rjp

pmerriman · #7 11-09-2011, 12:29 AM

Randy, thanks for the great work!
I was able to connect the blue/white wire from the amp to the switched 12v line and get music! My Son is very happy now.

Not sure what all the other extra wires are for but since he's happy with it...off he went back to school.

Thanks for working with me on it!

Paul

RANDY P · #8 11-09-2011, 02:59 AM

good news. as for the other shielded wires I think it may be to the lighter or illumination somewhere down by the ashtray.

rjp