Here is a site with a picture of it: http://ourworld.compuserve.com/homepages/kevtronics/factory3.htm
To do it correctly the speakers will have to be rewired and a new wiring harness installed.
If it does not have a factory installed harness - U-Haul has a kit with instructions to tap into OEM system
As of July 2013, there are several stores where a person can buy a wiring harness for the hazard signal switch for a 1977 Mercedes 450 SLC. Some of the names of the stores are Auto Zone, Advance Auto Parts, and O'Reilly Auto Parts.
Remove the covers from your 1988 Mercedes-Benz 300 speakers. Remove the speaker retaining screws. Remove the wiring harness from the back of the speakers.
There is a wiring harness most everywhere you look on that and any vehicle. Be more specific.
The purpose of the wiring harness is to help keep wires together instead of hanging freely. You can purchase a new wiring harness at any auto repair shop.
The wiring harness can be removed by unplugging all of the wires. The wiring harness is also held in place by several retaining screws. Remove the retaining screws.
Remove the wiring harness from the back of your 2007 Mercedes-Benz headlight. Remove the headlight retaining bolts. The headlight will come out. Reverse the process to install your new headlight.
The blower motor on a Mercedes Benz 300e is changed by disconnecting the wiring harness and unbolting the blower from its housing. The motor is then lifted away and a new blower motor connected.
The factory wiring harness for the trailers will plug in under the back of the vehicle in the area of the spare tire, the harness plugs into the wiring harness for the tail lights.
It depends on which Harness you are looking for.
the harness