Flex-a-lite Electric Fan Controller & Relay Kit 33095 – Compact Adjustable Temp Probe, 160–220°F, Black

Compact, weatherproof fan controller and relay kit that automatically switches electric radiator or engine cooling fans from about 160°F to 220°F and forces fan operation when the A/C is on.

This Flex-A-Lite Compact Adjustable Electric Fan Controller and Relay Kit (model 33095) is a ready-to-install solution for controlling single or dual electric cooling fans without the need for external relays. The kit bundles a potted control module for vibration and moisture resistance, a thread-in temperature probe, a 30-amp relay with inline fuse, wiring harnesses, and adapter bushings to fit common NPT port sizes. It’s designed for straightforward wiring in most automotive applications and gives you adjustable setpoints and optional manual override capability for precise engine temperature management and improved A/C performance.

How does this controller detect engine temperature and switch the fan?

The unit uses the supplied thread-in temperature probe to sense coolant or port temperature and compares it to an adjustable threshold inside the potted control module. When the sensed temperature reaches the chosen setpoint, the controller energizes the internal relay to run the fan(s). The A/C signal input forces the relay on whenever the air conditioning is operating, ensuring consistent cooling under load.

• Includes thread-in temperature probe and two adapter bushings (1/4", 3/8", 1/2" NPT compatibility).
• Adjustable activation range roughly 160°F–220°F for tailored cooling control.
• Internal 30-amp relay and inline fuse protect the electrical system.
• Potted electronics resist water and vibration for durability in engine bays.

What wiring and mounting hardware come with the kit?

The package contains the controller module pre-potted for protection, a 30A relay with an inline fuse, wiring leads with terminals, and mounting provisions for a manual override switch. Temperature probe adapter bushings let you thread the sensor into different port sizes, and the wiring includes standard terminals for quick connection to fans, power, and the A/C signal.

• Pre-wired control module and relay with fuse for simplified install.
• Wiring terminals and leads for power, ground, A/C trigger, and fan output.
• Adapter bushings to fit multiple NPT ports — no separate probe purchase needed.
• Provision for optional manual override switch to run fans on demand.

Which fans and vehicles are compatible with this Flex-A-Lite kit?

This controller is built for standard 12-volt electric cooling fans and is rated to handle typical single-fan or dual-fan setups up to the relay’s capacity. It’s suited to passenger cars, trucks, and many performance or aftermarket cooling systems that require automatic temperature-based fan control and A/C-linked operation.

• Rated for 12V systems and compatible with many 20A cooling fans (check combined draw vs. relay rating).
• Works with single or dual fan systems when wired appropriately.
• Adapter bushings enable use with common engine coolant ports or radiator fittings.
• Compact module size fits into most engine bays and mounting locations.

How do I adjust the activation temperature and override the controller?

The activation temperature is set via the controller’s internal adjustment, allowing you to fine-tune the fan-on threshold anywhere in the approximate 160°F–220°F window. The kit provides wiring provisions for a manually mounted switch if you want an override to force the fan on regardless of temperature for diagnostics, towing, or track use.

• Internal adjustment lets you set the fan-on point to match engine and thermostat characteristics.
• A/C input immediately commands fan operation when the compressor runs.
• Optional manual override switch wiring included for user-controlled fan activation.
• Clear wiring and protective fuse help prevent damage from incorrect installation.

Who this is for: The Flex-A-Lite 33095 controller and relay kit is aimed at DIY mechanics, performance enthusiasts, and repair shops that need a compact, reliable fan control solution without sourcing separate relays and sensors. It’s particularly useful when converting to electric fans, upgrading cooling performance for towing or hot climates, or replacing a failed factory fan controller with a weather-resistant, adjustable alternative.