I thought I saw the wiring diagram in the blue sticky regarding sound systems.

 

I'll recheck with some coffee,thanx!

 

Well after reviewing the stickies for custom radio install,wont work for what I'm trying to find,its for later years and they have different radio systems ,guess later had Bose systems http://www.benzworld.org/forums/r12...rg/forums/r129-sl-class/1360011-r129-custom-stereo-systems-138.html#post3701924
Just need the color code of the chassis radio wiring 1991 500SL, has to be a schematic some where? I found the pin out for my cars radio which has a Becker Grand prix,but in order to hook up my Pioneer need the color wires identified for speakers,power lead,ignition switch,illumination,auto antenna and so forth, haven't done this in a while maybe I'm missing something?

 

I got this from Crutchfield tech support last week. Not sure it's what you're looking for.
It appears there has been some amount of re-wiring done on my '91. I have not been able to get the larger door speakers (woofers?) to work yet. Any help would be appreciated.

Accessory 12 Volt; Pin 2; BK/BU

Constant 12 Volt; Pin 4; RD/WT

Chassis Ground; Pin 1; BN

Power Antenna; BK/RD* (quick-slide)

Illumination; Pin 3; GY/VT (2X)

Left Front Spkr +; Pin 5; BN

Left Front Spkr -; Pin 6; GY

Right Front Spkr +; Pin 7; RD/BN

Right Front Spkr -; Pin 8; BN

Left Rear + to Amp; Pin 9; WT

Right Rear + to Amp; Pin 11; BU

Common - to Amp; Pin 10; RD/YW (2X)

 

Ahha! this helps! thanks,will apply this to my homemade schematic, and post my results,thanks man!:thumbsup:
"common to amp pin 10:rd/yw(2x) " is this on the stereo head or do you have separate Amp on your car? my car is bone stock and don't think there's a separate Amp unit anywhere. think I have the same color combo as your car!

 

"common to amp pin 10:rd/yw(2x) " is this on the stereo head or do you have separate Amp on your car? my car is bone stock and don't think there's a separate Amp unit anywhere. think I have the same color combo as your car!

Sorry. Just saw your question. I'd have to look and see if I even have that rd/yw wire. There were a couple that didn't get used. Crutchfield said they appeared to be 'security' related.
They had originally prescribed a PAC SOEM-4 to serve as an adapter between the rear amplified speakers and the new Kenwood. However, I couldn't get any sound with that config. so I just wired the rears directly and it seems to work fine.

Sure looks like your car and mine are twins. I like the chromed wheels. I'm needing to do something with mine. Hadn't decided what yet.

 

Glad I could help!
I have figured out the problem with my 'rear' (aka door woofer) speakers as well.
Turns out the problem was between my ears... and my inability to realize that the original equipment didn't include speakers in the rear of the car.
That's all I'm going to say about it

 

I noticed 2 different radio schematics. Here is one of them, see if this could be the right one.

 

I have to redo all my radio stuff, I have pretty sad starting point...
Some previous owner have added those thick red wires, they go to speakers.
In the storage box behind right seat there are similiar red wires and also some RCA wires, have to figure out if those are going to larger speaker... There has been some kind of amplifier

 

What I did was make a wiring schematic for each location,helps to figure it out. if your replacing head unit you may want to install bass amp,I still need that,my sound is flat,all these cars had a bass amp installed at factory,it powered the big door speakers.

 

Where is that located? So far I sorted following wires that in picture. Also boxes behind passanger side floor, there is no amp?

 

Amp fot lower door speakers

There is indeed an amp for the lower door speakers. It is under the plastic panel in the pass foot well clearly labeled audio system. You will find the speaker wired there . Sorry for the very late post but thought it might help someone in the future.

 

Correct!

 

For anyone installing aftermarket radios, be careful about the speed sensor. The speed sensor signal is shared with the RST (roadster soft top) controller. If your top doesn't work properly after you have connected the speed sensor to your new radio, then that signal is probably getting distorted too much and the controller assumes the car is still in motion even after you stopped to open or close the top. I don't know what the proper impedance is for the speed sensor input.

Klaus

www.tophydraulicsinc.com

 

I didn't find a speed sensor on my 91,think it applies to later, but love my powered sub! Boom Boom,Boom!:devil

 

speed sensor

Most cars with electronics will have a speed sensor, originally used mainly for adjusting the idle speed but now also for increasing the radio volume to adjust for extra noise from the vehicle.

 

Hi all,
I am very happy with my 1996 sl 500. The aftermarket radio in it is awful, so I bought a sony with HD and usb from crutchfield's. They don't have a schematic for the bose system. I called Bose, no gots, I called becker, no gots; all I want is the what the harness looks like and which parts of the radio go to corresponding connections on the installed bose system....no pictures. A simple schematic and I have been looking for days before I get into the removal. Can anybody pls. help me?

Thanks in advance,

Xe

 

Good luck with that! your year is a tad different to mine,but what I did was search and found nothing for my year,so I went to the w124 and w126 forums and found schematics for radio systems,that helped me identify color of wires MB uses for radio chassis wiring,like brown is always ground etc. then I figured out where all my components were and made a schematic of my whole wiring in the car for radio,antenna,bass amp,speakers. then made a schematic for my new system adapting it to old system,lots of work but fun for me! be careful having an installer do it,how the hell are they going to know if no info is out there?

 

help



Do you still have the schematic you made?

 

wiring

This is probably not what you need but I used it when I was trying to figure out why my radio illumination was not working, it had a wire from the ISO plug missing, I was able to put a new ISO plug in to sort it.

MERCEDES Car Radio Stereo Audio Wiring Diagram Autoradio connector wire installation schematic schema esquema de conexiones stecker konektor connecteur cable shema

 

I'm having a bad dream! wake me up!:laugh

 

Hi everyone,
Thanks all for responses. However, none of them are what I asked about. What I want to know is which connections are on the Bose System so I can plug in the appropriate plugs from my new radio. I have called MB, Bose, been online for days and all I want is a simple diagram showing the left + -, R +-; front, rear, and sub. That's all. Can anybody help? Thanks, again in advance...oh I have a 1996 SL 500

 

Thank you! Time for me to get to work!

 

Back to lowesguy's original question in this old thread, here is a good selection of Mercedes wiring diagrams, including R129 radios starting from early 90s:
NEXEDGE StarFinder

The challenge is that diagrams are in Autodesk file format (.dwf). If the actual diagrams are shown as black screens, you need a viewer or browser add-on.
I can view them with 64-bit MS-IE v11 by installing the free viewer https://www.autodesk.com/products/design-review/download
(Edge or Firefox seem not work. Don't know about Chrome or 32-bit versions).

AK SL, hope this could help with your work... and others too struggling with the early Becker two-piece radios. Good luck!