Originally posted by 1998K
Planning to install relay for front low beam, I've seen other guy with a W124 that modified control unit of this devise, by simply interrumpt the dedicated track welding! Does someone know principle of bulb out control unit?

Fortunately high beam seems to be not controllod by this device!

Hi
hmm a high beam burn out will also trigger the bulb out light, the light comes on from circuit interruption.... probably triggered by the circuit voltage and or resistance change caused by the burned out bulb...