System Description (For Canada)

The headlamp system on vehicles for Canada contains a daytime light control unit. The control unit activates the high beam headlamps at approximately halt illumination whenever the engine is running. If the parking brake is applied before the engine is started, the daytime lights will not be illuminated. The daytime lights will illuminate once the parking brake is released. After that, the daytime lights will continue to operate even when the parking brake is applied.
Power is supplied at all times
^ through 15 A fuse [No. (38), located in the fuse block (in relay box)]
^ to headlamp relay-L terminals (1), (3) and (6), and
^ to daytime light control unit terminal (4).
Power is also supplied at all times
^ through 15 A fuse [No. (37), located in the fuse block (in relay box)]
^ to headlamp relay-R terminals (1), (3) and (6), and
^ to daytime light control unit terminal (3).
With the ignition switch in the ON or START position, power is supplied
^ through 10 A fuse [No. (31), located in the fuse block (in relay box)]
^ to daytime light control unit terminal (5).
Ground is supplied to daytime light control unit terminal (10) through body grounds (E13) and (E22).

HEADLAMP OPERATION
When the lighting switch is moved to the 2ND position, ground is supplied
^ to headlamp relay-L terminal (2)
^ through lighting switch terminal (3)
^ to lighting switch terminal (4)
^ through body grounds (M3) and (M90), and
^ to headlamp relay-R terminal (2)
^ through lighting switch terminal (1)
^ to lighting switch terminal (2)
^ through body grounds (M3) and (M90).
Then each headlamp relay is energized and power is supplied
^ from headlamp relay-L terminal (5)
^ to LH headlamp terminal (1),
^ to dimmer relay terminal (2), and
^ from headlamp relay-L terminal (7)
^ to daytime light control unit terminal (6)
^ to combination meter terminal (25) for HIGH BEAM indicator, and
^ from headlamp relay-R terminal (5)
^ to RH headlamp terminal (1)
^ from headlamp relay-R terminal (7)
^ to RH headlamp terminal (3), and
^ from daytime light control unit terminal (7)
^ to LH headlamp terminal (3).

Low beam operation
With dimmer switch in the LOW ("B") position, ground is supplied
^ to dimmer relay terminal (1)
^ through dimmer switch terminal (44)
^ to dimmer switch terminal (43)
^ through body grounds (M3) and (M90).
The dimmer relay is energized and ground is supplied
^ to terminal (2) of each headlamp
^ through dimmer relay terminal (5)
^ to dimmer relay terminal (3)
^ through body grounds (E13) and (E22).
With power and ground supplied, the low beam headlamps will illuminate.

High beam operation
When the dimmer switch is placed in HIGH ("A") position, dimmer relay is not energized and ground is supplied
^ to terminal (4) of RH headlamp and
^ to combination meter terminal (26)
^ through dimmer relay terminal (4)
^ to dimmer relay terminal (3)
^ through body grounds (E13) and (E22).
Ground is also supplied
^ to terminal (4) of LH headlamp
^ through daytime light control unit terminal (8)
^ to daytime light control unit terminal (2)
^ through dimmer relay and body grounds (E13) and (E22).
With power and ground supplied the high beam headlamps and HIGH BEAM indicator illuminate.

Flash-to-pass operation
When the dimmer switch is placed in PASS ("C") position, flash-to-pass operation is triggered regardless of the lighting switch position.
Ground is supplied
^ to headlamp relay-L terminal (2)
^ through dimmer switch terminal (8)
^ to dimmer switch terminal (9)
^ through body grounds (M3) and (M90), and
^ to headlamp relay-R terminal (2)
^ through dimmer switch terminal (5)
^ to dimmer switch terminal (6)
^ through body grounds (M3) and (M90).
Then each headlamp relay is energized and power is supplied to terminal (3) of each headlamp and terminal 025 of combination meter.
Ground is supplied to terminal (4) of each headlamp and terminal (26) of combination meter through dimmer relay and body grounds (E13) and (E22).
With power and ground supplied, the high beam headlamps and HIGH BEAM indicator will illuminate.