HI, I just bought a 1987 300E. I am replacing the aftermarket stereo with the original Becker 754. I have the power hooked up along with the antenna but can't figure out where the speakers hook up to. There is a 5 pin plug near the center of the back of the radio and two small connectiors with R and L above them over on the edge of the radio. I have the mating 5 pin plug that goes into the connector on the back of the radio and it has a brown wire, a green wire and a brown with blue stripe wire connected to it. The brown with blue stripe wire has a plug and appears to hook to an exterior ground lug on the radio and then an extension fron that that was cut. I have the same color wire under my dash. I am very confused.

If the two small connections are the speakers then what type of plug do you use to access them and what is the 5 pin plug in the middle of the radio for. Can anyone shed some light on this for me. Thanks, Tom

If you go to the Becker North America site

http://www.beckerautosound.com

and find your radio you'll find a diagram of the back of the radio and a description of each of the pins for the speaker connector. If someone has removed the connector from your car's harness, you'll have to get a connector (from Becker) and solder it to the harness using the diagram.

Most aftermarket head units come with a patch cable to go between the MB connector and the back of the their radio. But some people just get creative.

Thanks Richard, I went to the Becker site but all they showed under the harness was the power cord connector which I had figured out. I am still wondering what the other 5 connector plug does and how the speakers hook up.

I'm not very familiar with that model. At this point I would suggest contacting Becker NA by phone. They're not very good about responding to email. Or if you have a local auto radio shop which specializes in German cars. I would suspect the speaker connector would be 4 pin in that era. Although sometimes a connector with more pins is used for convenience and some pins unconnected. As you probably noticed the Becker site had a speaker connector for sale. PN below schematic of power connector. Maybe it comes with instructions.

As for the other connector, in newer radio designs that connector is used to control things like power for a retractable antenna or CD changer.

Also, you might want to post in the Audio subforums of other MB enthusiast sites.