Headlamps - Main Beam Operation

Headlamps - Main Beam Operation
When the lighting switch is moved to the flash or main position, the feed from fusible link 10 in the engine compartment fusebox, passes through the switch contacts. The feed is connected on a UW wire to the passenger compartment fusebox, where it passes through fuses 3 and 22.

The IDM senses the headlamp main beam request and through internal circuitry, provides a feed, on a US wire, to the main beam warning lamp in the instrument pack. The main beam warning lamp is connected from the instrument pack to earth on a B wire to earth header C0551.

LH headlamp
The feed from fuse 3 is connected on an S wire from the passenger compartment fusebox to the LH headlamp and illuminates the LH main beam bulb. The earth path from the LH headlamp is connected on a B wire to earth eyelet connector C0563-1.

RH headlamp
The feed from fuse 22 is connected on a UO wire from the passenger compartment fusebox to the RH headlamp and illuminates the RH main beam bulb. The earth path from the RH headlamp is connected on a B wire to earth eyelet connector C0559-1.

Daylight Running Lamps Supply
The feed from fuse 13 in the engine compartment fusebox is connected to the coil of the daylight running relay and the IDM integral with the passenger compartment fusebox.

When the engine is started, the IDM senses, through internal circuitry, that the engine is running and provides an earth for the daylight running relay coil. The energized coil closes the contacts of the daylight running relay allowing the feed from fuse 4 in the passenger compartment fusebox to pass through the relay contacts.