Best Dual Fan Relay Kit for Automotive Cooling Upgrades
If you’re upgrading your vehicle’s cooling system with a dual fan setup, a dual fan relay kit is essential for reliable temperature control and wiring simplicity. This guide highlights five top options, explaining which buyers each kit serves best—from daily drivers to performance builds. Each section includes practical pros, limitations, and who should choose that kit. A quick comparison table summarizes key features to help you decide at a glance.
| Product | Best For | Key Benefit | Limitations |
|---|---|---|---|
| FASTSTORM Dual Electric Fan Relay Kit | Daily drivers needing solid 60A capacity | Comprehensive kit with temperature switch and wiring harness | Includes many accessories; installation complexity depends on wiring experience |
| ZOZOMOTORS Dual Electric Fan Relay Kit | Budget-conscious builders | Clear labeling and full wiring diagram | Thermostat requires attention to engine cooling relationship |
| FASTSTORM Dual Electric Fan Relay Kit (Another variant) | Mid-range upgrades | 60A relay with robust components | Best for standard dual-fan setups; ensure compatibility with your fans |
| FASTSTORM Digital Radiator Fan Switch Kit | Tech-savvy enthusiasts needing precise control | Adjustable temperature range with LED readouts | Electronic display requires power and setup |
| 12V 40 Amp Dual Electric Fan Relay Kit | Simple, single-setup needs | Single fan-ready wiring with 185/175°F switch | Lower amp rating may limit high-power dual-fan configurations |
FASTSTORM Dual Electric Fan Relay Kit — 60A, 4 Pin, 185/185 On/Off
Best for: Everyday drivers seeking reliable dual-fan cooling with a complete kit. This option includes a 60A relay, a comprehensive wiring harness, a temperature switch, and multiple adapters. The temperature switch turns the fans on at approximately 200 °F and off at 185 °F, supporting steady engine cooling. It fits 10″, 12″, 14″, and 16″ fans, making it versatile for many radiator configurations. Use this kit if you want an all-in-one solution that minimizes additional parts and guesswork.
Why selected: The kit’s full component list reduces the need to source separate pieces, and the switch-on/off temperatures align with typical cooling needs for many engines. The combination of color-coded wiring and a clear diagram helps less-experienced installers complete the setup with fewer errors.
Cautions: Ensure your fan sizes and amperage demands match the 60A relay. The included fuses and fuse holders require careful routing to protect the circuit in case of shorts.
ZOZOMOTORS Dual Electric Fan Relay Kit — 40A, 185/175 On/Off
Best for: Builders on a tighter budget or those adding a single- or limited dual-fan setup. This kit provides clearly labeled wires, a color-coded harness, and a straightforward wiring diagram. The temperature switch activates at about 185 °F and deactivates around 175 °F, with a 3/8 inch pipe thread and a 1/2 inch adapter included. Note that a thermostat around 160 °C may be required for some engine cooling systems when used with this switch.
Why selected: The emphasis on clear labeling and an included diagram reduces ambiguity during installation, making it a solid choice for DIYers who prefer a straightforward, documented approach.
Cautions: If you’re using higher temperature thermostats (e.g., 180 °F variants), confirm that engine cooling will still reach the desired shutoff point to avoid prolonged fan operation. The kit includes a 40A relay, which should be matched to the fan load.
FASTSTORM Dual Electric Fan Relay Kit — 60A, 4 Pin, 185/175 On/Off
Best for: Upgrades seeking efficient cooling with reliable current handling. This kit brings a 60A relay, a 4-pin configuration, and a temperature switch guaranteeing activation at 185 °F and deactivation at 175 °F. It supports 10″, 12″, 14″, and 16″ fans and ships with wiring, fuse components, and adapters for a smooth install. Choose this if you plan a robust dual-fan installation where steady cycling matters for engine life and performance.
Why selected: The emphasis on robust electrical protection and a complete component set makes it a strong option for users replacing aging systems or adding dual fans to keep engine temperatures in check during demanding driving conditions.
Cautions: Ensure the fan load does not exceed 60A. Verify that the included wiring harness routing is suitable for your vehicle’s engine bay layout to avoid interference with belts or hoses.
FASTSTORM Digital Radiator Fan Switch Kit — 12V/24V, 104°F–230°F
Best for: Tech-focused buyers needing precise, programmable control over one or two fans. This digital switch provides an adjustable range from 104 °F to 230 °F, with a dual display showing real-time and set temperatures in °C and °F. It’s compatible with 12V and 24V systems and supports replacement for part #0444/DC0444. The dual-fan operation with a delay start helps prevent electrical overload when both fans engage.
Why selected: The ability to set exact temperatures and view them in real time delivers a higher level of control for performance vehicles, off-road rigs, or hot climates where precise cooling management matters.
Limitations: The LED display and digital control may require proper wiring and power supply considerations. Ensure your vehicle’s ECU or accessories won’t conflict with the display or its power draw.
12V 40 Amp Dual Electric Fan Relay Kit
Best for: Simple, lower-power dual-fan upgrades or single-fan setups where a compact, straightforward kit is preferred. The kit includes a waterproof relay, a 3/8″ or 1/2″ NPT thermostatic switch with 185 °F on and 175 °F off, and a fuse block. It’s designed to work with any 12-volt system and supports single-fan configurations efficiently.
Why selected: The combination of a waterproof relay and a standard thermostatic switch makes this a reliable choice for users focusing on a simple, dependable installation without extra bells and whistles.
Cautions: The 40A rating may be limiting for high-demand dual-fan setups. Verify your fan amperage requirements to ensure compatibility with the kit’s relay.
Buying Guide
What should I consider when choosing a dual fan relay kit?
Fuel economy and engine longevity are influenced by how well you control fan operation. Key factors include amperage rating, thermostat activation temperatures, compatibility with your radiator fan sizes, and the completeness of the included wiring harness. For most everyday drivers, a 60A relay kit with a clear wiring diagram and a 185 °F/175 °F or similar on/off range provides reliable performance.
Single vs. dual fans: which kit is right?
Single-fan setups typically require smaller relays and simpler wiring. If you plan to run two fans, ensure the kit’s amperage capacity and wiring can handle the combined load. Dual-fan kits with 60A relays generally offer better headroom for temperature swings and high-demand driving.
Temperature switches and accuracy
Thermostatic switches determine when the fans engage. Precision matters in hot climates or high-performance engines. Look for switches with clearly stated on/off temperatures and compatible fittings (pipe thread size and adapters). Some kits also offer adjustable or digital controls for finer tuning.
Wiring diagrams and installation ease
Wiring diagrams simplify installation and reduce mistakes. Kits that label wires by color and include comprehensive diagrams save time and reduce the risk of miswiring. If you’re new to wiring, prioritize kits with step-by-step diagrams and labeled connectors.
Durability and environmental resistance
Consider waterproof or weather-resistant relays if you operate in wet or dusty conditions. Look for components that resist vibration and temperature extremes to sustain reliability in automotive environments.
FAQ
- What is a dual fan relay kit used for? It controls two cooling fans in a vehicle’s cooling system, using a relay and a thermostat or digital control to switch fans on and off according to engine temperature.
- Can I install a dual fan kit myself? Yes, most kits include wiring diagrams and color-coded harnesses. However, basic electrical knowledge and careful routing of wires in the engine bay are important for safe operation.
- What amperage rating should I look for? If you have two fans or high-demand cooling, a 60A relay is common. Ensure the total current draw does not exceed the relay rating.
- Do these kits require special thermostats? Many kits include thermostatic switches with defined on/off temperatures. Some kits support adjustable or digital temperature controls for greater precision.
- Is a digital radiator fan switch better than a standard thermostat? Digital or adjustable switches offer precise setpoint control and real-time readouts, which is beneficial for performance tuning and hot climates.
- What if my vehicle uses 24V systems? Some kits support 24V, particularly the digital switch options. Always verify voltage compatibility before purchase.