Fexhull Thermal Fan Controller 12V/24V - 104–230°F Digital Dual-Fan with LED Display

Fexhull 0444 is a compact digital thermal fan controller that automatically switches radiator fans on and off between 104°F and 230°F for 12V or 24V systems.

This compact controller is built to add reliable automatic cooling control to cars, trucks, industrial equipment and retrofitted cooling systems. It displays current and set-point temperatures on an LED readout, remembers settings after power loss, and supports either single- or two-fan setups with a delayed second-fan start to prevent electrical overload. Designed to match OE form factors and wired for straightforward installation, it’s a practical upgrade or replacement for systems that need precise thermal switching.

How does the controller manage temperature and display readings?

The unit continuously monitors coolant or air temperature via the included sensor and shows both the live temperature and the programmed trigger on its digital screen. When the measured temperature reaches the programmed threshold, the fan output engages; it turns off again once the temperature falls a fixed amount below the set point for energy-efficient operation.

• Adjustable range: 104°F to 230°F (40°C to 110°C)
• Dual C/F display options and power-off memory
• Automatic shutoff 5°C below the set temperature to reduce cycling
• Real-time LED shows current and preset temperatures simultaneously

Can it run both 12V and 24V fans and how are relays handled?

The Fexhull 0444 supports dual-voltage environments; it’s designed for 12V systems and can be used with 24V fans when paired with appropriate 24V relays. For higher-voltage fans, install standard 24V relays to prevent overloading the controller’s outputs, ensuring long-term reliability.

• Compatible with 12V systems directly; 24V use requires matching relays
• Max tested voltage for the controller electronics is 15V; use relays for higher-voltage loads
• Dual-relay wiring supported for two-fan setups
• Designed to protect controller from fan current by isolating loads via relays

What happens when two fans are connected—does it prevent electrical overload?

The controller can manage either one or two fans and includes logic to sequence the second fan so both don’t draw peak current simultaneously. The second fan engages 10 seconds after the first, reducing inrush overlap and lowering the risk of tripping fuses or stressing the alternator.

• Single-speed output for each fan, with independent relay switching
• 10-second delay before the second fan starts to reduce peak current
• Works with A/C systems via override wiring to improve cooling under load
• Pre-programmed microcontroller handles sequencing and timing

How difficult is installation and what hardware is included?

Installation is aimed at technicians and DIYers: color-coded wires and a 3m sensor lead simplify routing in tight engine bays. The harness uses thicker-gauge wires for current capacity and includes provisions for A/C override or manual toggle wiring so the controller suits a range of vehicle configurations.

• Color-coded wires: red (B+), black (B-), yellow (ignition+)
• 3 meter sensor cable for flexible sensor placement
• Detailed installation instructions included for common setups
• Wires sized for reliable current flow and long-term use

Who is this for: The Fexhull 0444 controller is intended for vehicle owners, fleet managers, and industrial equipment operators who need reliable automatic fan control with precise temperature set points. It fits users upgrading older mechanical thermostats, replacing worn factory controllers, or adding thermostatic control to custom cooling systems—especially where dual-fan sequencing, C/F display flexibility, and durability are required. It’s not a medical device and is meant for automotive and industrial cooling applications only.