Daytime Running Lamp: Description and Operation

SYSTEM OUTLINE

The current from the FL MAIN is always flowing from the MAIN fuse to HEAD relay (Coil side) to TERMINAL 3 of the daytime running light relay (Main), from DOME fuse to TERMINAL 1 of the daytime running light relay (Main) and from the ALT fuse to Taillight relay (Coil side) to TERMINAL 5 of the daytime running light relay (Main).
When the ignition SW is turned on, the current flowing through the GAUGE fuse flows to TERMINAL 10 of the daytime running light relay (Main).

1. DAYTIME RUNNING LIGHT OPERATION
When the engine is started, voltage generated at TERMINAL L of the generator is applied to TERMINAL 9 of the daytime running light relay (Main). When the light control SW is set to DRL position, the signal is input to TERMINAL 13 of the daytime running light relay (Main) (USA). When the automatic light control sensor signal is input to the daytime running light relay (Main) (Canada). 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 18 of the relay.
This activates the daytime running light relay (Main) and the HEAD relay is turned to on, so the current flows from the MAIN fuse to TERMINAL 1 of the DRL NO.2 relay to TERMINAL 2 to HEAD LH (UPR) fuse to TERMINAL 1 of the headlight LH (High) to TERMINAL 2 to TERMINAL 2 of the headlight RH (High) to TERMINAL 1 to TERMINAL 3 of the DRL NO.3 relay to TERMINAL 4 to GROUND, causing the headlights to light up (Headlights light up dimmer than normal brightness.). Once the daytime running light system operates and the headlights light up, the 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, the headlights remain light up even through current is no longer output from TERMINAL L of the generator. If the ignition SW is then turned off, the headlights go off.
If the engine is started with the parking brake lever released (Parking brake SW off), the daytime running light system operates and headlights light up when the engine starts.

2. HEADLIGHT OPERATION
When the light control SW is switched to HEAD position and the dimmer SW is set to LOW position, causing the daytime running light relay (Main) and the HEAD relay to turn on, so the current flows from the MAIN fuse to HEAD relay (Point side) to H-LP LH (LWR), H-LP RH (LWR) fuses to TERMINAL 1 of the headlights to TERMINAL 2 to GROUND, causing the headlights to light up at normal intensity.
When the light control SW is switched to HEAD position and the dimmer SW is set to HIGH position, the signal from the dimmer SW is input to the daytime running light relay (Main). This activates the daytime running light relay (Main) and the HEAD relay is turned on, so the current flows from the MAIN fuse to HEAD relay (Point side) to H-LP LH (LWR), H-LP RH (LWR) fuses to TERMINAL 1 of the headlights to TERMINAL 2 to GROUND, activating the DRL NO.2 relay. This causes current to flow from TERMINAL 1 of the DRL NO.2 relay to TERMINAL 2 to HEAD LH (UPR) fuse to TERMINAL 1 of the headlight LH (High) to TERMINAL 2, HEAD RH (UPR) to TERMINAL 5 of the DRL NO.3 relay to TERMINAL 3 to TERMINAL 1 of the headlight RH (High) to TERMINAL 2 to DRL NO.4 (Point side) to GROUND, causing the headlights to light up at high beam and the high beam indicator light to light up.
When the dimmer SW is switched to FLASH position, the signal from the dimmer SW is input to the daytime running light relay (Main). This activates the daytime running light relay (Main) and the HEAD relay is turned on, so the current flows from the MAIN fuse to HEAD relay (Point side) to H-LP LH (LWR), H-LP RH (LWR) fuses to TERMINAL 1 of the headlights to TERMINAL 2 to GROUND, activating the DRL NO.2 relay, and also flows from the HEAD LH (UPR) fuse to TERMINAL 1 of the headlight LH (High) to TERMINAL 2, HEAD RH (UPR) to DRL NO.3 relay (Point side) to TERMINAL 1 of the headlight RH (High) to TERMINAL 2 to DRL NO.4 (Point side) to GROUND, causing the headlights to light up at high beam and the high beam indicator light to light up.

3. AUTOMATIC LIGHT CONTROL OPERATION
When the daytime running light is operating and the automatic control sensor detects a decrease in the ambient light, the automatic light control operation starts. At the same time, daytime running light relay (Main) is activated, so current flows from the ALT fuse to the taillight relay (Coil side) to TERMINAL 5 of the daytime running light relay (Main), and the MAIN fuse to the HEAD relay (Coil side) to TERMINAL 3 of the daytime running light relay (Main), activating both the taillight relay and the DRL NO.4 relay, so that the taillights and headlights light up.
When the automatic light control sensor detects an increase in the ambient light, the ignition SW is turned to off, the light control SW is turned to HEAD position, and the automatic light control operation stops.