3315541 - E2012 MAIN BEAM HEADLAMPS - Functional description

Functional description

The main beams are controlled by electronic Check device M45 , which receives control signals from the switches and controls the bulbs while also checking the various lines. The supply for the Check device M45 arrives directly from the battery at pin 1 of connector C and 6 of connector E via fuses F17 and F15 of junction unit B2 for the right and left branches of the lights, respectively. The ignition-controlled supply (15/54) arrives via relay T1 and fuse F9 of junction unit B2 at pin 3 of connector B: pin 8 of connector C is earthed. The circuit for the main beam headlamps is operated by the steering column switch unit H5, placing the switch in the main beam headlamps position or closing the 'flasher' contact: in the former case the signal reaches pin 9 of connector B of M45 and in the latter case pin 11 of connector B. The command for the solenoid that opens the lamp dimmer, leaves from pin 11 of connector C of M45, thereby switching the gas discharge bulb from dipped to main beam; the signal for the spot lights (special halogen bulb) leaves from pins 5 and 4. The line for pin 10 of connector A of M45 lights up the 'main beams on' warning light inside instrument panel E50 - pin 6 of connector C - while pin 16 of connector A acts as an earth.