Stereo connections for 300E 1988?

[Swift300E]

Hi Everybody,

I've just got my first ever Mercedes and, no doubt as with all newcomers, I was wondering if I could pick your collective brains please. I am buying a Haynes manual, but it won't be here for several days, and I'm sure you guys know more anyway!

I'm fitting a new stereo and was wondering if anyone knows about the connections. There are four power leads on a four pin socket, numbered 1 to 4 (two red & two black). I'm assuming that one red is the switched positive and one red is the continuous positive (a.k.a. the "memory" wire). I don't know why there are two earths, but I imagine I can connect them both into my stereo's one earth?

Am I correct in my assumptions and, if so, which is the continuous positive and which is the switched?

Also, my car does not have the rear speakers fitted and I am going to fit some. Are the wires already there somewhere? No problem if not, as I'm going to need to lay CD autochanger cabling through to the boot anyway, which leads me to my last question: does anyone have any tips on how to do this without ruining carpets etcetera?

Thanks in advance for any help you can all give and thanks to everyone involved with this excellent site.

Regards,

Marcus.

 

[Howard]

Hi Everybody,

I've just got my first ever Mercedes and, no doubt as with all newcomers, I was wondering if I could pick your collective brains please. I am buying a Haynes manual, but it won't be here for several days, and I'm sure you guys know more anyway!

I'm fitting a new stereo and was wondering if anyone knows about the connections. There are four power leads on a four pin socket, numbered 1 to 4 (two red & two black). I'm assuming that one red is the switched positive and one red is the continuous positive (a.k.a. the "memory" wire). I don't know why there are two earths, but I imagine I can connect them both into my stereo's one earth?

Am I correct in my assumptions and, if so, which is the continuous positive and which is the switched?

Also, my car does not have the rear speakers fitted and I am going to fit some. Are the wires already there somewhere? No problem if not, as I'm going to need to lay CD autochanger cabling through to the boot anyway, which leads me to my last question: does anyone have any tips on how to do this without ruining carpets etcetera?

Thanks in advance for any help you can all give and thanks to everyone involved with this excellent site.

Regards,

Marcus.

Hi Marcus, and welcome

Not sure about the connections, but should be the work of minutes with a multimeter to work them out ...

I'm presuming its a w124 series, in which case , you can run the wires under the passenger footwell in the cable tray , along the sill by pulling the sill cover off sharply (it will come, it is just stiff ) and tuck them under the rear carpet ....

When you come to get them into the boot , it is a bit more fiddley as the petrol tank is behind the rear seat on a w124 and hence it has a substantial firewall ...

Take the base and back of the passenger side rear seat out ( 2 bolts ) , and near the top you will find a grommet that you can use to get wires through .... i think from memory , the electric aerial wire goes through there along with some other stuff .... but there is plenty of room ...

Good luck

H

 

[grober]

Some Illustrations

Heres some pics of a power amp install in a W124 to illustrate what Howard has told you already. http://www.mercedesshop.com/Wikka/W124AudioAmp
and some pics of speaker detail
http://www.mercedesshop.com/Wikka/W124Stereo
and forgetting my manners welcome to the forum.

 

[LastMinute]

There are four power leads on a four pin socket, numbered 1 to 4 [HIGHLIGHT](two red & two black)[/HIGHLIGHT].

That's not original wiring. The original wires to the radio power connector were:

• Red/white - permanent +12V from fuse 9
• Black/yellow - accessories switched +12V from fuse 1
• Grey/purple - illumination (not dimmed)
• Brown - earth

Also, my car does not have the rear speakers fitted and I am going to fit some. Are the wires already there somewhere?

No.

 

[Swift300E]

Gentlemen,

This is superb information. Many thanks to you all.

For LastMinute, yes you're right. I had accidentally looked at the wires coming out of the plug/socket, not going in from the car, so the colours are as original, which makes life easier.

What a welcoming bunch you are. I look forward to a long association with this club. Thanks again.

Regards,

Marcus.