Flex-a-lite Compact Adjustable Electric Fan Controller & Relay Kit — Black, Thread-in Probe

The Flex-A-Lite Compact Adjustable Electric Fan Controller and Relay Kit is a self-contained 12V fan control system with thread-in temperature probe that switches single or dual electric radiator fans between roughly 160°F and 220°F and forces fan operation whenever the A/C is on.

This compact kit simplifies electric fan installations by combining a potted control module, a 30-amp relay, inline fuse, wiring and a thread-in temperature sensor so you don’t need separate external relays. Designed for automotive cooling systems, the controller works with common NPT ports using included adapter bushings and supports most 12-volt cooling fans up to 20 amps per circuit. The rugged construction and potted electronics help resist moisture and vibration, making it suitable for engine bays and roadside conditions.

How does the temperature control work and what range can I expect?

The controller uses the supplied thread-in temperature probe to monitor coolant or sensor block temperature and activates the fan when the measured value reaches your set threshold. The activation range is adjustable, offering practical control from about 160°F to 220°F so you can tune cooling for street, performance, or towing conditions.

• Adjustable activation approximately 160–220°F
• Thread-in probe provides direct temperature feedback
• Includes two adapter bushings for 1/4-, 3/8-, and 1/2-inch NPT fittings
• Fine-tune to reduce cycling or improve cooling under load

Will this kit work with my electric fan and A/C system?

The Flex-A-Lite kit is engineered to operate most 12V electric radiator or engine fans and is compatible with single- and dual-fan setups. It also senses A/C engagement and forces the fan to run whenever the air conditioning is active, improving A/C performance and helping maintain condenser and engine temperatures under load.

• Rated for 12-volt fans, compatible with up to 20 amps per fan circuit
• Built-in relay and inline fuse remove the need for extra relays
• A/C input keeps fans running when the compressor is on
• Wiring and terminals included for typical installations

How durable and easy to install is the controller?

Installation is straightforward: thread the probe into an available port, mount the compact control module, connect the relay and fuse, and use the supplied wiring and terminals. The module’s potted electronics protect against water and vibration, extending service life in harsh under-hood environments.

• Potted module for moisture and vibration resistance
• Includes relay, inline fuse, wiring, and terminals
• Provision for optional manual override switch
• Adapter bushings simplify probe installation in different ports

Who is this for? The Flex-A-Lite Compact Adjustable Fan Controller and Relay Kit suits car owners, DIY mechanics, and performance tuners who want a compact, reliable way to control electric cooling fans without adding separate relays. It’s ideal for vehicles converted to electric fans, aftermarket radiators, or A/C upgrades where automatic, adjustable temperature control and A/C-triggered operation improve cooling performance and component longevity. Backed by a one-year manufacturer warranty, it provides an accessible solution for most 12V automotive cooling needs.