Behind the glove compartment
 

On my 1987 560SL there is a little door in the back part of the glove compartment. I opened this and there are two connectors.... a 16 pin one and an 8 pin one. They were unplugged. I plugged them in and the lights started flashing and there was a constant clicking sound. I unplugged them. They sit atop one of the a/c ducts. What are these for? I also spotted a wire that has a double pronged connector in it and instead of a bulb on the top the two pronged wire led to a tiny black circular ceramic disk on it. It isn't connected to anything but should be. Does anyone know where this goes?