Date registered: Apr 2008
Vehicle: Departed 1998 SL500 (and the Pano is in Bogota)
Location: Right here.
Mentioned: 3 Post(s)
Quoted: 449 Post(s)
Brake wear sensor normally has 2 wires encapsulated in plastic. When the brake pad wears down, the sensor rubs against the disk and the plastic got worn down. The two exposed wires shorted out themselves against the metal disk to complete the circuit, turning on the warning light. If yours only has 1 wire, may be when it touches the disk, it shorts into ground to complete the circuit.