When do you turn off the headlight switch?
Step 3 – These running lights are used when visibility is low such as at dusk, or when fog has covered the road. Step 4 – The main control for the headlight switch is the headlights themselves, in this position the headlight will remain “ON” until the ignition switch is turned off, or the switch is removed from this position.
Which is the first position on a headlight switch?
The first position on a headlight switch is the running light illumination, this position is used to power up the running light system only. Running lights are used when visibility is low such as at dusk or when foggy.
Why does my head light switch not work?
This design helps prevent heat and premature failure of the headlight switch. If the parking lights work, but the headlights do not, the headlight relay may be at fault.
How does the BCM work on a headlight switch?
When the switch is turned to the parking light or headlight position, the signal is sent back to the BCM. The BCM then acts as the either a control for the headlight relay, or controls the headlights directly. Testing this system is similar to testing a 12-volt system.
What happens when you turn off the automatic headlamps?
The instrument panel won’t be lit up either. When it begins to get dark, the automatic headlamp system will switch from DRL to the headlamps. When you turn the headlamp switch off, the headlamps will go off, and your DRL lamps will illuminate, provided it is not dark outside [Does this mean if it IS dark the DRL’s will not come on?
When the switch is turned to the parking light or headlight position, the signal is sent back to the BCM. The BCM then acts as the either a control for the headlight relay, or controls the headlights directly. Testing this system is similar to testing a 12-volt system.
How does the headlamp control work on a truck?
Turn the control clockwise to operate the lamps. The headlamp control has four positions: (Off): Turning the control to this position turns off the Daytime Running Lamps (DRL) and the automatic headlamps. [My truck doesn’t do this]
How do you replace a headlight relay switch?
Move the negative lead to the output wire for the headlight relay, then turn the switch to the headlights setting and check the meter. Replace the switch if there is excessive resistance in either position. On this type of system, the body control module does most of the work. The switch receives a 5-volt reference from the BCM.