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, TERMINAL 6 of integration relay, TERMINAL 17 of Dimmer SW, daytime running light relay No.2 (Coil Side), to TERMINAL 17 of the daytime running light relay. When the Ignition SW is turned ON, voltage from the GAUGE fuse is applied to TERMINAL 2 of the daytime running light relay.

1. DAYTIME RUNNING LIGHT OPERATION
When the Engine starts, voltage from TERMINAL L of the generator (Alternator) is applied to TERMINAL 11 of the daytime running light relay. If the parking brake pedal is depressed (Parking Brake SW ON) at this time, the relay and the daytime running light do 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 8of the daytime running light relay. This activates the daytime running light relay, turning ON the daytime running light relay No 2. Current also flows from the MAIN fuse to daytime running light relay No.2 (Point Side) --> HEAD (LH-UPR) Fuse --> Headlight HI LH -->Headlight HI RH --> TERMINAL 4 of daytime running light relay No.3 --> TERMINAL 2 --> GROUND, causing the headlights to light up at half their normal brightness.
Once the daytime running light relay has been activated and the headlights light up, the Headlights remain ON even if the parking brake pedal 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 6 of Light Control SW --> TERMINAL 16 --> 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. No.4 (Coil Side) --> GROUND activating relay No.3 and No.4.
When the Dimmer SW is at HIGH position, TERMINAL 9 of the Dimmer SW outputs a signal to TERMINAL 16 of the daytime running light relay to activate it. This turns ON daytime running light relay No.2. So current flows from daytime running light relay No.2 (Point Side) to the HEAD (LH-UPR) Fuse --> Headlight HI LH -->daytime running light relay No.4 (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.4 (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 17 of the Dimmer SW --> TERMINAL 18 --> 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 and No.4. Then TERMINAL 9 of the Dimmer SW outputs a signal to TERMINAL 16 of the daytime running light relay, activating the daytime running light relay so that current flows to Headlight HI like it does for HIGH position. This causes all Headlights to light up.