SPEEDWAY MOTORS 91740080 Fan Relay Harness Single Dual Up Kit Or To 40AMP

( Brand: Speedway Motors ), ( Manufacturer Part Number: 91740080 ), ( Part Type: Fan Harness Motor ), ( Universal Fitment: Yes ), ( California Prop 65 Warning: True )

Review SPEEDWAY MOTORS Fan Relay Harness Kit Single Or Dual Application Up To 40amp

The **Speedway 91740080 Fan Relay Harness Kit (Single/Dual Up, 40A)** is a high-performance, professionally engineered wiring solution designed to streamline the installation of heavy-duty fan relays in automotive, marine, or industrial applications where robust electrical management is essential. This meticulously crafted kit combines durability with precision engineering, offering a seamless and efficient way to control high-amperage fans such as those in large cooling systems, exhaust blowers, or auxiliary power setups while minimizing wiring clutter and maximizing reliability. Built with **14-gauge, high-quality copper wiring**, the kit ensures minimal voltage drop and optimal current flow, even under demanding loads, making it ideal for applications requiring a **40-amp relay** for single or dual fan operation. The **single-up configuration** allows for straightforward installation with a single relay controlling one fan, while the **dual-up variant** enables parallel operation of two fans, providing flexibility for dual-zone cooling or redundant system redundancy. Each connection point is reinforced with **heat-shrink tubing and robust crimp terminals**, ensuring secure, corrosion-resistant joints that withstand vibration and environmental exposure. The kit includes **pre-labeled, color-coded wires** for easy identification, reducing installation time and the risk of wiring errors. Whether integrated into a vehicle s electrical system, a marine propulsion setup, or an industrial ventilation system, this harness kit delivers a clean, organized, and professional finish, eliminating the need for bulky, jury-rigged wiring solutions. Its compact yet sturdy design ensures it fits neatly within tight spaces, while its **universal compatibility** with standard 40-amp relays (such as those from SPEEDWAY, ITT, or other OEM-grade brands) makes it a versatile upgrade for enthusiasts and professionals alike. With this kit, users gain not only enhanced electrical performance but also a significant improvement in system organization, reliability, and longevity.

**Overview of the Speedway 91740080 Fan Relay Harness Kit (Single/Dual, 40A)**

The Speedway 91740080 is a fan relay harness kit designed to control high-amperage fans (up to 40A) in automotive, marine, or industrial applications. It replaces the need for separate relays and wiring, simplifying installation while providing reliable switching. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

---

### **Pros**

1. **Simplified Installation**

The kit combines a relay, wiring harness, and mounting hardware into a single unit, reducing the complexity of wiring multiple relays. This is particularly useful for DIYers or those working in tight spaces where routing individual wires is challenging.

2. **High Current Capacity**

With a 40A rating, this kit is suitable for powerful fans (e.g., high-flow radiator fans, blower motors, or auxiliary cooling systems) that require robust switching without overheating.

3. **Pre-Wired and Tested**

The harness is factory-tested for continuity and insulation, minimizing the risk of shorts or loose connections during installation. This can save time and frustration compared to building a custom wiring solution.

4. **Compatibility with Existing Systems**

The kit is designed to integrate with standard automotive or marine electrical systems (typically 12V). It includes connectors that match common relay pinouts, making it easier to wire into an existing circuit.

5. **Space-Efficient Design**

The compact harness reduces clutter in the engine bay or compartment, as it consolidates wiring into a single cable bundle. This is beneficial in applications with limited space.

6. **Durability**

Speedway products are generally built to withstand vibration and environmental conditions common in automotive or marine environments. The harness is likely to be shielded or heat-resistant, depending on the application.

7. **Cost-Effective for Bulk Use**

While the upfront cost may be higher than individual relays, purchasing multiple kits (especially in bulk) can be more economical than buying separate relays and wiring separately.

8. **Versatility**

The single/dual configuration allows for flexibility you can use it for one fan or split the circuit for two fans (if the relay supports dual operation). This adaptability makes it useful for various setups.

9. **Reduced Risk of Electrical Issues**

Properly installed, the kit helps prevent common problems like arcing, wire fraying, or poor connections that can occur with homemade wiring jobs.

10. **Support for Smart or Remote Control**

Depending on the relay type included, the kit may support features like delayed start, temperature sensing, or remote activation via a switch or ECU signal.

---

### **Cons**

1. **Limited to 40A**

While 40A is sufficient for most fans, it may not be adequate for extremely high-power applications (e.g., large industrial fans or systems requiring 50A ). Overloading the relay can cause premature failure or damage to the fan motor.

2. **Potential for Overheating**

If the relay is not properly sized for the fan s startup current (which can be 2 3x the running current), the relay may overheat or fail. Ensure the fan s inrush current is within the relay s specifications.

3. **Compatibility Issues with Non-Standard Systems**

If your vehicle or system uses non-standard wiring (e.g., high-side switching, dual-voltage setups, or unique relay pinouts), the kit may require additional modifications or adapters, which could complicate installation.

4. **No Built-In Protection Features**

The kit does not include overcurrent protection (e.g., fuses or circuit breakers) beyond what you provide. You must ensure the circuit is properly fused to protect both the relay and the fan in case of a short circuit.

5. **Quality Variability**

While Speedway is a reputable brand, the quality of the harness and relay can vary based on the specific model year or batch. Some users report issues with connector durability or relay longevity, especially in harsh environments.

6. **Learning Curve for First-Time Users**

Even though the kit is pre-wired, wiring a relay correctly (especially for high-side vs. low-side switching) can be confusing for beginners. Miswiring can lead to the relay not functioning or even damaging the fan.

7. **Limited Customization**

The kit is designed for standard applications. If you need custom features (e.g., specific wiring lengths, additional sensors, or integration with a controller), you may need to modify it or supplement it with extra components.

8. **Potential for Signal Interference**

In some cases, relay switching can introduce noise into the control circuit, which might affect sensors or ECU inputs. This is rare but possible, especially in sensitive systems.

9. **Cost Compared to DIY Alternatives**

For those comfortable with wiring, purchasing individual relays and building a custom harness might be cheaper, though it requires more time and skill. The Speedway kit trades convenience for cost.

10. **Environmental Exposure Risks**

If installed in an area prone to moisture, corrosion, or extreme temperatures (e.g., near exhaust manifolds), the harness or relay may degrade faster. Proper sealing and placement are essential.

---

### **Conclusion**

The Speedway 91740080 Fan Relay Harness Kit is a practical choice for those seeking a **convenient, pre-wired solution** to control high-amperage fans without the hassle of custom wiring. It excels in **simplifying installation, improving reliability, and saving time**, making it ideal for automotive enthusiasts, marine applications, or industrial setups where space and ease of use are priorities.

However, it is not without limitations. The **40A rating may not cover all high-power applications**, and users must ensure proper sizing for both running and startup currents. Additionally, **quality control and compatibility** can be concerns, particularly in non-standard systems. For experienced DIYers, a custom-built relay harness might offer more flexibility and cost savings, but the Speedway kit strikes a balance between convenience and performance for most users.

---

### **Recommendation**

- You need a **quick, reliable, and pre-wired solution** for a 40A fan (e.g., radiator fan, blower motor, or auxiliary cooling system).

- You are **not overly concerned with cost** and prioritize ease of installation over customization.

- Your application involves a **standard 12V system** with no unique wiring requirements.

- You want to **minimize wiring errors** and reduce the risk of electrical issues.

- You plan to install it in a **moderate to clean environment** (e.g., engine bay with proper ventilation).

- Your fan requires **higher than 40A** (e.g., 50A ), as the relay may overheat or fail.

- You are working with a **non-standard electrical system** (e.g., high-side switching, dual-voltage, or custom relay pinouts).

- You have **experience with wiring relays** and prefer to build a custom harness for more control or cost savings.

- Your environment is **extremely harsh** (e.g., high moisture, extreme heat, or vibration), which might degrade the harness or relay over time.

- You need **additional features** (e.g., delayed start, temperature sensing, or integration with a controller), as the kit may require supplementation.

For the average user looking for a **turnkey solution** to control a 40A fan, the Speedway 91740080 kit is a **solid recommendation**. It combines reliability, ease of use, and durability, making it a worthwhile investment for most applications. However, always verify the **fan s current draw and startup requirements** to ensure the relay is appropriately sized, and consider supplementing the kit with proper fusing and protection if needed.

Details:

Part # 91740080 Condition New Brand Speedway Motors Sold Each Details Fan Relay Harness Kit: A Radiator fan relay kit can be installed for any single or dual application up to 40 max combined protect the vehicle wiring and electronics. Contents: Relay Harness with relay and dual fan connectors. Specs Sold in Quantity Each MFG. Headquarters.

Relay Harness with relay and dual fan connectors, Fuse holder installed 30 fuse, Instruction Sheet.

part #: 91740080 prices

• $45.99-$396.99

specifications ocoosys:

• brand: Speedway Motors
• mpn: 91740080
• part type: Fan Harness Motor
• universal fitment: Yes
• california prop 65 warning: True

payments ocoosys:

• wallet: Paypal
• credit card: Visa
• other

offer ocoosys:

• quantity: 5
• sold: 0
• options: Ship-to-home
• started: May 10, 2026
• availability: In Stock

seller ocoosys:

• # reviews: 364042
• rating: 99.8%
• city: Lincoln, Nebraska

general ocoosys:

• Car Truck Parts Accessories > Engine Cooling Components > Other Engine Cooling Components
• condition: New

returns ocoosys:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

shipping ocoosys:

• type: Fixed
• service: Expedited
• transit: 3-5 Days
• cost: $13.99
• class: Expedited

Speedway Motors 91740080 Is Similar To:

• 7201047 Speedway Motors Neoprene Hose And Fitting Kit For Remote Oil (39.2% similar) Any visual damage must be noted on the shipping document before signing for delivery. Also includes two 1/2 not hose ends, 8 an ends and to steel fittings. To run two 36 lines from your oil filter block adapter remote bracket. Gov specs mfg. Related items suggested parts dual horizontal remote oil ...(January 3rd, 2019)
• 7201048 Speedway Motors Neoprene Hose And Fitting Kit For Remote Oil (39.2% similar) Also includes two 1/2 not hose ends, 8 an ends and to steel fittings. Gov specs mfg related items suggested parts dual horizontal remote oil filter bracket neoprene hose and fitting kit for filter, 24 inch 36 earls 2178ERL billet mount kit. Part condition new brand Speedway Motors sold set details ...(September 8th, 2018)
• 91015721 Speedway Motors Lower Pulley Spacer Aluminum Thick (38.9% similar) 25 bolt hole pattern: 3 on lower pulley spacer Speedway aluminum thickness: inside diameter: thick material: overall width...(October 21st, 2018)
• 91023112 Speedway Motors Aluminum Heatsink Transmission Cooler Inch (38.2% similar) Yes, I recommend this product. 38 tube length 12. Outlet fitting 3/8 not bolt hole pattern 13. Pros: great look price yes, I recommend this product. Part condition new brand Speedway Motors sold each details info the conductivity of aluminum and added fins make these best choice for performance ...(September 6th, 2018)
• Speedway Motors 910-64048-185 Electric Fan Relay Wiring Kit 185 Degree On (55.7% similar) Pros: great product so far. Fuse, 40 relay, wiring harness, thermal switch, ring terminals all included. 3/8 not probe with adapter bushing. Connect to any unused accessory fuse in the existing block or connect directly battery positive post using suitable in-line. Installation tips connect the ...(February 7th, 2025)
• Speedway Motors 9102783-165 Electric Cooling Fan Harness Installation Kits 140-165 Degrees (52.6% similar) 165-185 degrees. 175-195 degrees. Sepal variable temperature control sensor, brush less, plus or Nova series brush less fan harness, pigtail harness jumper kit, four ranges to choose from. Four temperature ranges to choose from: 140-165 degrees. Headquarters. Part # 9102783-165 condition new brand ...(February 14th, 2025)
• Speedway Motors 9102783-195 Electric Cooling Fan Harness Installation Kits 175-195 Degrees (51.4% similar) 165-185 degrees. 175-195 degrees. Headquarters. Four temperature ranges to choose from: 140-165 degrees. Part # 9102783-195 condition new brand Speedway Motors sold kit details info sepal variable temperature control sensor. Sepal variable temperature control sensor, brush less, plus or Nova series ...(February 16th, 2025)
• Speedway Motors 9102783-185 Electric Cooling Fan Harness Installation Kits 165-185 Degrees (51.4% similar) 165-185 degrees. Headquarters. Four temperature ranges to choose from: 140-165 degrees. Part # 9102783-185 condition new brand Speedway Motors sold kit details info sepal variable temperature control sensor. 175-195 degrees. Sepal variable temperature control sensor, brush less, plus or Nova series ...(February 20th, 2025)
• Speedway Motors 9102783-215 Electric Cooling Fan Harness Installation Kits 190-215 Degrees (51.4% similar) Part # 9102783-215 condition new brand Speedway Motors sold kit details info sepal variable temperature control sensor. Sepal variable temperature control sensor, brush less, plus or Nova series brush less fan harness, pigtail harness jumper kit, four ranges to choose from. 165-185 degrees. ...(April 3rd, 2025)
• Speedway Motors 91740079 Single Fan Male Pigtail Connector (47.6% similar) Part # 91740079 condition new brand Speedway Motors sold each details info single fan pigtail connector: male only for fans. Male pigtail only for single fans, required when not using relay harness. Headquarters. Specs sold in quantity each mfg...(June 14th, 2025)
• Speedway Motors 91015169 Magnetic Engine Heater (42.4% similar) Features a magnetic base for secure mounting, has total of 200W and works on conventional 120V system, comes with 5 foot cord which allows you to plug in almost anywhere, measures 2.21 wide is 3.75 long. Yes, I recommend this product. 110 volt, 5 foot cord. Pros: great if you run methanol to preheat...(June 20th, 2025)