Headlamp: Description and Operation

1. DAYTIME RUNNING LIGHT OPERATION
When the Engine is started, voltage generated at 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 Relay is not activated so the Daytime running light system does not operate. If the parking brake lever is then released (Parking Brake SW OFF), a signal is input to TERMINAL 8 of the Relay. This activates the Relay, so current flows from battery to the Head Relay (Point Side) --> TERMINAL 1 of the DRL Relay --> TERMINAL 4 --> Head (LO, LH), (LO, RH) fuse --> TERMINAL 1 of Headlights --> TERMINAL 3 --> TERMINAL 1 of Daytime running light resistor --> TERMINAL 2 --> Ground. this causes the Headlights to light up (The Headlights Light Up Dimmer Than Full Brightness.).
Once the Daytime running light system operates and Headlights light up, Headlights remain ON even if the parking brake lever is pulled up (Parking Brake SW ON)

If the Engine stalls and the Ignition SW remains ON, Headlights remain lighted up even though current is no longer output from TERMINAL L of the generator. If the Ignition SW is then turned OFF, the Head lights go OFF. If the Engine is started with the parking brake lever released (Parking Brake SW OFF), the Daytime running light system operates and the Headlights light up when the Engine starts.

2. HEADLIGHT OPERATION
When the light control SW [Comb. SW] is switched to Head position, current flows from the DRL fuse --> TERMINAL 4 of Daytime running light Relay no.4 --> TERMINAL 3 --> TERMINAL 1 of diode no.1 --> TERMINAL 2 --> TERMINAL 13 of light control SW [Comb. SW] --> TERMINAL 11 --> Ground, activating Daytime running light Relay no.4. current then flows from the Head (LH LO), (RH LO) fuse to TERMINAL 1 of the Headlights --> TERMINAL 3 --> TERMINAL 2 of Daytime running light Relay no.4 --> TERMINAL 1 --> Ground,causing the Headlights to light up at normal intensity. When the Dimmer SW [Comb. SW] is switched to the High position, the signal from the Dimmer SW [Comb. SW] is input to the Daytime running light Relay (main). This activates the Relay and current flows from TERMINAL 1 of the DRL Relay --> TERMINAL 3 --> TERMINAL 17 of the Daytime running light Relay (Main), activating the DRL Relay.
This causes current to flow from TERMINAL 1 of the DRL Relay --> TERMINAL 2 --> Head (HI LH), (HI RH) fuse --> TERMINAL 2 of Headlights --> TERMINAL 3 --> TERMINAL 1 of Daytime running light Relay no.4 --> TERMINAL 2 --> Ground, causing the Headlights to light up at high beam.
When the Dimmer SW [Comb. SW] is switched to Flash position, the Daytime running light Relay (Main) is activated and current flows from TERMINAL 1 of the DRL Relay to TERMINAL 2. Current from the DRL fuse flows TERMINAL 4 of Daytime running light Relay no.4 --> TERMINAL 3 --> TERMINAL 1 of Diode no.1 --> TERMINAL 2 --> TERMINAL 1 of Diode no.2 --> TERMINAL 2 --> TERMINAL 14 of Dimmer SW [Comb. SW] --> TERMINAL 9 --> Ground, and also flows from the Head (HI LH), (HI RH) fuse --> TERMINAL 2 of Headlights --> TERMINAL 3 --> TERMINAL 2 of Daytime running light Relay no.4 --> TERMINAL 1 --> Ground, causing the high beam to operate.