Overview
The Traxxas Wire Harness TRX3478 is an essential component for RC enthusiasts in the UK looking to upgrade their cooling capabilities on compatible Traxxas models. Specifically designed for use with the Traxxas #3475 VXL-6s cooling fan, this wire harness provides a reliable connection between your receiver and the cooling fan, enabling efficient thermal management during high-performance driving sessions. Whether you're pushing your brushless RC truck to its limits with speed gearing or engaging in extended maximum-power runs, proper cooling is critical to maintaining optimal performance and protecting your valuable electronics from heat damage.
This wire harness is an integral accessory for any serious RC car enthusiast in the UK who operates high-output systems, particularly those running 6S LiPo battery configurations or speed-focused setups. As featured in Traxxas's full-option Sledge build project, this harness represents professional-grade equipment endorsed by the manufacturer for serious performance driving. If you're building a track-ready or high-speed RC monster truck, buggy or similar brushless vehicle, the cooling fan wire harness is a crucial upgrade that can prevent costly electronic failures and extend the service life of your speed control and motor.
Compatible with the Traxxas Sledge and other models equipped with TQi receivers, this wire harness delivers straightforward installation and reliable performance. It's designed to plug directly into the receiver for power delivery, making it an accessible upgrade even for intermediate RC enthusiasts. The harness comes included with the #3475 cooling fan, but replacement units are essential for anyone building multiple high-performance systems or requiring additional harnesses for different configurations.
Key Features
- Direct Receiver Connection — The wire harness plugs directly into your TQi receiver for power delivery, eliminating the need for complex wiring modifications and ensuring a reliable electrical connection that won't fail during demanding driving sessions.
- Compatible with #3475 VXL-6s Cooling Fan — Specifically engineered for use with Traxxas's professional-grade VXL-6s cooling fan, this harness ensures proper voltage delivery and thermal control when running high-output speed configurations.
- Designed for High-Performance Applications — The harness is built to support extended maximum-power driving sessions, making it essential for anyone running speed gearing on 6S LiPo batteries or engaging in competitive RC driving in the UK.
- Professional-Grade Construction — Traxxas manufactures this harness to the same high standards as their complete RC cars and trucks, ensuring durability and reliability that matches professional RC racing expectations.
- Prevents Thermal Shutdown — By enabling active cooling of your speed control during maximum-speed runs, this harness helps prevent the thermal shutdown protection from activating unnecessarily, allowing you to maintain consistent performance.
- Motor Protection — Proper cooling through this harness system helps keep motor temperatures below the critical 170°F (77°C) threshold, preventing permanent power output reduction or other heat-related damage to your brushless motor.
- Essential for Speed Running — If you're planning to run optional 18-tooth pinion and 46-tooth spur gearing to achieve 70+ mph on your Sledge or similar platform, this cooling harness becomes a critical component for reliable operation.
Technical Performance
The Traxxas Wire Harness TRX3478 is engineered specifically for cooling system integration on high-performance brushless RC vehicles running 6S LiPo battery systems. When paired with the #3475 VXL-6s cooling fan, this harness delivers essential thermal management capabilities for RC cars and trucks pushed to their limits. The harness plugs into the receiver's power circuit, drawing electrical current to drive the cooling fan during intensive driving sessions. This is particularly crucial when operating speed-focused gear ratios on Traxxas Sledge 1/8 scale 4WD platforms or similar high-output systems where motor and ESC temperatures can quickly exceed safe operating limits. The engineering behind this harness reflects Traxxas's commitment to protecting expensive electronic components; without active cooling, a motor exceeding 170°F (77°C) risks permanent performance degradation or catastrophic failure. The harness represents the difference between a reliable high-speed system capable of sustained 70+ mph running and one prone to thermal protection shutdowns that interrupt driving and reduce performance. For UK RC enthusiasts serious about competitive driving, extended speed runs, or maximum-output performance, this wire harness is not optional—it's essential infrastructure for system longevity and consistent performance.
What's in the Box
- Traxxas Wire Harness for #3475 cooling fan
- Receiver connection interface
Frequently Asked Questions
- What is the Traxxas Wire Harness TRX3478 used for? — This wire harness provides the electrical connection between your TQi receiver and the Traxxas #3475 VXL-6s cooling fan, enabling active cooling of your speed control during high-performance driving. It plugs directly into the receiver for power delivery, allowing the fan to operate automatically and help shed heat during maximum-power pulls and speed running.
- Do I need this wire harness if I'm running speed gearing? — If you're planning to install optional high-speed gear ratios (such as 18-tooth pinion and 46-tooth spur gearing) to achieve 70+ mph on your Traxxas Sledge or compatible platform, this cooling harness becomes essential. Speed gearing puts significantly more demand on your motor and speed control, generating excessive heat that requires active cooling to prevent thermal shutdown and permanent damage.
- Is this compatible with all Traxxas models? — This harness is specifically designed for Traxxas models equipped with the #3475 VXL-6s cooling fan and TQi receiver systems. The Traxxas Sledge is the primary application in the full-option build project, but compatibility extends to other models with compatible receiver architecture.
- What models is this compatible with? — The wire harness is compatible with Traxxas Sledge in all colour variants (Blue, Orange, Green, Red), as well as other Traxxas models featuring TQi receivers and provision for the #3475 cooling fan accessory.
- How do I install this wire harness? — Installation is straightforward: the harness plugs into your receiver for power delivery. It requires no soldering or complex modifications. Simply connect it to the designated power port on your TQi receiver and secure it in place. The harness comes with the #3475 cooling fan for integrated installation.
- Why is active cooling important for RC cars? — When running high-output brushless systems on 6S LiPo batteries at maximum power, your motor and speed control generate significant heat. Without active cooling, temperatures can exceed 170°F (77°C), which may permanently reduce motor power output or cause catastrophic electronic failure. The cooling fan driven by this harness helps maintain safe operating temperatures, enabling longer, more consistent performance during extended driving sessions.
- What temperature is too hot for my Traxxas motor? — Traxxas recommends monitoring motor temperature after each full-speed run, particularly when operating speed gearing. If the motor exceeds 170°F (77°C), you risk permanent performance reduction or other heat-related damage. Active cooling through the #3475 fan and this harness helps keep temperatures within safe limits.
- Can I use this harness as a replacement? — Yes, this is a replacement harness for anyone who needs an additional connection interface for multiple cooling fan setups or requires a spare harness for system maintenance and repair.
- Is this suitable for beginners? — The wire harness itself is straightforward to install for anyone with basic RC knowledge. However, it's primarily relevant for intermediate to advanced drivers who are running high-performance configurations and speed gearing, which require more technical understanding of thermal management and electronic protection.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the Traxxas Wire Harness (for use with #3475 cooling fan) TRX3478 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
- Brand: Traxxas
- Model Number: TRX3478
- EAN: 020334347800
- Product Type: Wire Harness for Cooling Fan
- Compatible Fan: #3475 VXL-6s Cooling Fan
- Compatible Receiver: TQi Receiver
- Connection Type: Direct receiver power connection
- Primary Application: Traxxas Sledge Belted 1/8 4WD Brushless Electric Monster Truck (all colours: Blue, Orange, Green, Red)
- Use Case: High-performance speed running and thermal management for 6S LiPo systems
- Recommended Motor Temperature Monitoring: Keep below 170°F (77°C) to prevent permanent damage
- Thermal Protection: Enables active cooling to prevent speed control thermal shutdown during maximum-power runs
- Installation: Plugs directly into receiver with no soldering required
- Included with: #3475 VXL-6s Cooling Fan (replacement harness sold separately)
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- For orders above £120, we offer delivery to most mainland UK addresses. For orders under £120, we can still deliver to Northern Ireland and the outlying isles, as long as the item can be sent by Royal Mail, weighs less than 30kg, and fits within 61cm × 46cm × 46cm. Some highland and remote areas may carry an extra delivery charge as couriers often apply surcharges in these locations. If you live in one of these areas, feel free to contact us before ordering so we can confirm the delivery options and costs for you.
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