For the young folks in Gen Z and later, having a floor dimmer switch in a vehicle sounds unconventional.
Early auto engineers used this design after realizing drivers could multitask, and operating this switch using the foot improved safety because drivers could keep both hands on the wheel.
Therefore, you might find this feature in old cars, and you can wire it in your new vehicle if you find it better than having the switch on the stalk.
Here’s a step-by-step guide on how to wire a floor dimmer switch in your vehicle.
Table of Contents
- What Is a Floor Mounted Dimmer Switch?
- Floor-Mounted Dimmer Switch Terminals
- Floor-mounted dimmer Switch Installation
- Why Use a Dimmer Switch?
- Wrap Up
What Is a Floor Mounted Dimmer Switch?
The most basic car headlight system has high beam and low beam circuits. So, unlike the dimming switches in houses that feature a gradual dimming mechanism, those found in cars have three states. These are off, low, and high.
Some have two states (low and high) and use an external switch to control power flow to the dimmer circuit.
A car headlight switch in off, low-beam, and high-beam states
A floor-mounted dimmer switch has a similar operating mechanism, but as the name suggests, it sits on the floor. The device is near the footrest or pedals in most cars, making it a foot-operated dimmer switch.
But unlike the stalk-mounted switch, this floor dimmer switch is a push-button type because the foot cannot twist a knob. And it usually only has two states, which are low beam and high beam.
Therefore, when wiring the unit, you need a headlamp switch on the dashboard to control the power flow to the dimmer switch.
The brake and accelerator pedals in an automatic transmission vehicle (a floor dimmer switch sits near these pedals)
Floor-Mounted Dimmer Switch Terminals
This headlamp dimmer switch has three terminals.
- Common pin
- Headlight terminal
- High beam pin
The setup must have an external switch to regulate power flow to this device. Power from this external switch comes into the foot dimmer switch via the common pin, which then functions as an SPDT (Single Pole Double Throw).
An SPST vs. SPDT switch operation
This switch throws power to the headlight terminal by default, keeping the vehicle headlights in the low-beam state.
Pushing the headlight dimmer switch cover throws the power connection from the common pin to the high-beam terminal.
This high-beam circuit also connects to an indicator light on the dashboard to show the high-beam headlights are on.
Car headlight interface symbols that indicate the headlamp condition on the dashboard
Floor-mounted dimmer Switch Installation
Follow these steps to install and wire this dimmer switch.
Step 1: Disconnect the Power Supply
This safety measure is vital to protecting you and the vehicle. And you don’t have to disconnect both battery terminals. Remove only the negative terminal battery lug to prevent ground faults if any power wire touches the car’s body or chassis.
Step 2: Remove the Old Dimmer Switch
Floor mounting this switch in a vehicle that doesn’t have one from the factory is challenging but doable.
You’ll have to reroute the wires from the stalk switch on the steering column to the floor, which involves removing parts of the steering column and the dashboard.
However, if your car comes with this component, remove the old one and undo the wiring connections on its terminals.
Most have quarter-inch spade terminals, so you can pull the terminals off the original switch or cut the wires to crimp the replacement.
Step 3: Wire the New Dimmer Switch
If you recall, dimmer switch assemblies have three terminals. Connect the power line from the dashboard headlight switch to the common pin.
Next, attach the headlight terminal to the low-beam wire and the high-beam pin to the high-beam wire.
You can use your vehicle’s wiring diagram to guide you through this process. But wiring this component is arguably the most straightforward technical task you can do in your car.
Ensure you insulate the terminals or joints before proceeding to step four.
Step 4: Mount the New Dimmer Switch
Complete the installation process by fastening the new dimmer switch to the floor using the screws removed earlier or those included in the package. After that, mount the headlight dimmer switch cover on the button and test the system.
A full-beam dashboard light indicator (it usually glows in blue in most cars)
Why Use a Dimmer Switch?
Modern vehicles feature automatic dimming headlights that eliminate human input for beam control when driving. But some still have this feature for those who appreciate manual control.
Dimmer switches help give you excellent visibility when driving without burning the eyes of oncoming drivers, especially on two-way roads.
You should dim your headlamps when approaching oncoming vehicles, then switch back to a high beam after the car passes to give you better visibility.
Similarly, you need high-beam headlights when entering lowly lit areas, such as tunnels or underground parking lots. Dimmer switches come in handy in such situations.
Lastly, you need this switch for driving to communicate with other drivers. For instance, you can flicker your headlamps when at an intersection or junction to prompt the other driver to go ahead.
Although auto engineers are behind the idea of shifting the dimmer switch from the floor to the stalk switch, drivers have different preferences.
Therefore, if you like the foot dimmer switch design, you can install this feature in your vehicle.
If your car already has this feature, replacing it is as easy as using the four steps described above.
You can learn more about headlamp switches in this article, and comment below to share your thoughts and sentiments or if you need further clarification. We’ll be happy to help.