Headlamp: Description and Operation

Voltage is always applied from the MAIN fuse, through the headlight relay (coil side) to TERMINAL 5 of the daytime running light relay (main), TERMINAL 6 of the integration relay, TERMINAL 14 of the dimmer SW, dimmer relay (daytime running light relay no.2) (coil side), to TERMINAL 17 of the daytime running light relay (main). When the ignition SW is turned ON, voltage from the GAUGE fuse is applied to TERMINAL 2 of the daytime running light relay (main).

1. DAYTIME RUNNING LIGHT OPERATION
When the engine starts, voltage from TERMINAL 'L' of the generator is applied to TERMINAL 11 of the daytime running light relay (main). If the parking brake lever is pulled up (parking brake SW ON) at this time, the daytime running light system does not operate. When the parking brake is released (parking brake SW OFF), a signal is output from TERMINAL 1 of the parking brake SW to TERMINAL 8 of the daytime running light relay (main). This activates the daytime running light relay (main), turning ON the dimmer relay (daytime running light relay no.2). Current also flows from the main fuse to the dimmer relay (daytime running light relay no.2) (point side) --> HEAD (LH-UPR) fuse --> headlight HI LH --> headlight HI RH TERMINAL A-5 of the daytime running light relay no.3 TERMINAL A-3 --> GROUND, causing the headlights to light up at approx. 20% of their normal brightness.

Once the daytime running light relay (main) has been activated and the headlights light up, the headlights remain ON even if the parking brake lever is engaged again (parking brake SW ON)

2. HEADLIGHT OPERATION
When the light control SW is at HEAD position and the dimmer SW at LOW position, current flows from the headlight relay (coil side) to TERMINAL 6 of the integration relay --> TERMINAL 7 --> TERMINAL 13 of the light control SW TERMINAL 11 --> GROUND, activating the headlight relay.

This causes current to flow from the headlight relay (point side) to the HEAD LWR fuse --> headlight LO GROUND, causing the headlights to light up at normal brightness. Simultaneously, current flows from the DRL fuse --> daytime running light relay no.3 (coil side) --> GROUND, activating relay no.3. When the dimmer SW is at HIGH position, TERMINAL 12 of the dimmer SW outputs a signal to TERMINAL 16 of the daytime running light relay (main) to activate it. This turns ON dimmer relay (daytime running light relay no.2). So current flows from the dimmer relay (daytime running light relay no.2) (point side) to the HEAD (LH-UPR) fuse --> headlight HI LH --> daytime running light relay no.3 (point side) --> GROUND, and from the HEAD (RH-UPR) fuse --> daytime running light relay no.3 (point side) --> headlight HI RH --> daytime running light relay no.3 (point side) --> GROUND, causing the headlights to operate at HI.

When the dimmer SW is at FLASH position, current from the headlight relay (coil side) flows to TERMINAL 14 of the dimmer SW --> TERMINAL 9 --> GROUND, activating the relay. Simultaneously, current from the headlight relay (point side) flows to headlight LO, lighting up headlight LO and activating daytime running light relay no.3. then TERMINAL 12 of the dimmer SW outputs a signal to TERMINAL 16 of the daytime running light relay (main), activating the daytime running light relay (main) so that current flows to headlight HI like it does for HIGH position. This causes all headlights to light up.