What are auxiliary switches in an overhead console?

The overhead-console auxiliary switches are extra, labeled control buttons that power and manage additional accessories without cluttering the dash. They are typically wired to relays and fuses to control devices like lights, air compressors, or other equipment, and are commonly found in the overhead module for easy reach while driving.

In many models, the overhead console houses map lights, sunglasses holder, and various control buttons, including the auxiliary switches. This article explains what they are, where they appear, how they work, and what to consider for safe use and installation.

Definition and purpose

Auxiliary switches are a set of small, labeled buttons (often marked AUX1, AUX2, etc.) built into or added to the overhead console. Their function is to send a control signal to a relay or power circuit that energizes an accessory device. This arrangement keeps aftermarket or optional equipment neatly integrated with the vehicle’s interior controls and reduces the need for extra dash-mounted switches. The switches themselves are low-current inputs; the high-current load powers the accessory through relays and fuses.

Where they are found

These switches are commonly installed in the overhead console, near the rearview mirror, within reach of the driver. They are a staple on many late-model trucks, SUVs, and some cars with factory or dealer-installed accessory packages. The exact number and labeling (for example AUX1–AUX6) vary by model and trim level, and aftermarket kits can add or replace the standard set.

Common uses for auxiliary switches include powering and controlling additional equipment without loading the dash with extra controls:

• Off-road and auxiliary lighting (roof lights, bumper lights, light bars)


• Air compressors and tire-inflation systems


• Winches and other high-current accessories via relay-controlled circuits


• Portable fridges, power inverters, or other 12V devices


• Other aftermarket add-ons wired into dedicated circuits (rooftop racks, awnings, etc.)

The above list illustrates typical roles for overhead-console auxiliary switches. Exact configurations depend on the vehicle and the installed wiring harness or accessories.

How they work

Auxiliary switches act as low-current inputs that energize relays or control modules. When you press a switch, it sends a signal to a relay coil or a control unit, which then closes the high-current circuit that powers the connected device. The actual power often comes from a fused supply tied to the vehicle’s battery or the dedicated power distribution system. Some setups include indicator LEDs on the switch to show when the accessory is active, and ignition-sensing can determine whether the circuit is ignition-switched or constant power.

In factory or dealer-installed systems, the overhead console may include a pre-wired harness and a relay pack designed to handle specific loads. Aftermarket installations may require additional wiring, relays, fuses, and proper gauge voltage cables to meet safety and performance standards. Correct labeling and wiring are essential to avoid misoperation or accidental battery drain.

Safety and installation considerations

Using auxiliary switches safely involves planning for electrical load, proper protection, and correct installation practices. Here are key points to keep in mind:

• Electrical load and fuse protection: ensure each accessory’s current draw stays within the switch and relay rating, and use the correct fuse size for protection.


• Wiring and gauges: use appropriate wire gauge for high-current devices and route wires away from heat sources, moving parts, and water exposure.


• Relays and control modules: install relays (and any control modules) to isolate high-current devices from the vehicle’s body electronics and to simplify troubleshooting.


• Ignition versus constant power: decide whether circuits should be active only with ignition or remain powered independently, to avoid battery drain.


• Labeling and visibility: ensure switches are clearly labeled and, if illuminated, that indicators are reliable to prevent accidental use.


• Professional installation for high-current gear: for devices like winches or air compressors, consider professional installation to ensure safety, reliability, and compliance with vehicle electrical standards.

Proper planning, adherence to vehicle electrical guidelines, and following manufacturer instructions are essential when configuring or expanding overhead-console auxiliary switches.

Practical considerations for users

When using auxiliary switches, it’s important to know what each switch controls and how the accessory interacts with the vehicle. Keep a maintenance log for fuse and relay checks, and periodically inspect wiring for wear or corrosion. If you’re adding new accessories, choose components with automotive-rated wiring, appropriate fusing, and compatibility with the vehicle’s electrical system to avoid interference with critical systems.

Summary

Auxiliary switches in an overhead console are a convenient way to manage additional vehicle accessories from a centralized, accessible location. They function by sending signals to relays that power high-current devices, while the switches themselves handle low-current control. Availability, labeling, and wiring of these switches vary by make and model, but the core concept remains the same: enhanced control and streamlined integration of aftermarket or factory-installed equipment, with careful attention to electrical safety and proper installation.

In short, auxiliary switches provide a tidy, efficient way to operate extra gear from above your head, without cluttering the dashboard, while requiring thoughtful wiring and maintenance to keep the system safe and reliable.

What is the purpose of an auxiliary switch?

Auxiliary switches are used to control and monitor accessories, providing a way to power add-on devices or get information about the status of electrical systems like circuit breakers and motor starters. In vehicles, they allow users to easily power accessories like lights or winches, while in industrial settings, they monitor the position of equipment or trigger alarms based on a circuit's status. 
In vehicles

• Powering accessories: They provide pre-wired and fused power for add-on devices like winches, fog lights, and other electrical equipment, so you don't have to add your own aftermarket wiring.
• Control: They give you direct control over these accessories, and some systems, like the "upfitter" switches in a Ford truck, are designed to be easily wired to various devices. 

In industrial and electrical applications

• Remote monitoring: In circuit breakers, auxiliary switches provide remote feedback on the breaker's status (open or closed), which helps operators monitor the system from a distance and identify any issues.
• Status indication: They can activate indicator lights or alarms based on the state of a main circuit or piece of equipment.
• Control of secondary functions: In motor control, they can be used to operate other devices, such as a cooling fan, when the motor is running. 

How they work

• Vehicle examples: The switches are typically linked to a power distribution box, which then routes power to various locations in the vehicle. When a switch is activated, it completes a circuit and provides power to whatever is wired to it. For safety, it's often recommended to leave the engine running to maintain the battery charge when using high-draw accessories. 
• Circuit breaker examples: An auxiliary switch's contacts are mechanically linked to the main contacts of the circuit breaker. When the breaker is opened or closed, the auxiliary switch changes state, which can be used to signal the change to another system. 

What does an auxiliary switch do in HVAC?

An auxiliary switch is a secondary switch that works in tandem with a primary device, such as a circuit breaker, motor starter, or relay. Its primary role is to indicate the position of the main device—whether it's open or closed—allowing it to signal the status of the circuit or equipment it's connected to.

What are Jeep auxiliary switches used for?

Jeep auxiliary (aux) switches are used to power aftermarket accessories like lights, winches, air compressors, and lockers. They provide a convenient way to add electrical devices by wiring them to pre-installed power and control points, often with programmable settings for on/off, momentary, and different power sources (ignition or battery).
 
This video shows how to program the aux switches on a Jeep Wrangler: 57sWicked FabzYouTube · Sep 5, 2024
Common uses for Jeep aux switches 
This video shows the factory auxiliary switches on a Jeep Wrangler JL and Gladiator JT: 1mKC HiLiTESYouTube · Jun 27, 2019

• Lighting: This is a very common use, including light bars, ditch lights, fog lights, rock lights, and rear backup lights. 
• Winch: A winch can be wired through an aux switch to control its power and solenoid. 
• Air compressor: These switches are frequently used to power an air compressor for inflating tires or using air tools. 
• Lockers: Some owners use aux switches to control front and rear air lockers. 
• Power and charging: Aux switches can power 12v outlets, USB ports, or an inverter for charging devices or running small appliances. 
• Monitoring and safety: They are useful for powering dash cams, GPS units, or other monitoring equipment. 
• Other accessories: This includes things like a CB radio, a cooling fan, a battery isolator for a second battery, or even power windows. 

How they work

• The switches connect to the vehicle's electrical system through pre-routed wiring, which is often found in the engine bay. 
• Each switch typically has a maximum amperage rating, so it's important to check the requirements of your accessory before connecting it. 
• Many factory-installed systems allow you to program the switches through the infotainment system to control how they operate, such as: 
  • On/Off (Latching): The switch stays on until you press it again.
  • Momentary: The accessory is only active while the switch is being pressed.
  • Power Source: The switch can be set to work only when the ignition is on or to draw power directly from the battery. 

How does an auxiliary switch work on a circuit breaker?

An auxiliary switch is a small but essential supplementary switch that works in conjunction with a larger primary switching device, most commonly a circuit breaker. It's mechanically linked to the circuit breaker's operating mechanism, meaning its state (open or closed) directly reflects the breaker's position.