| No. | Part No. | Name |
|---|---|---|
| 1 | WG9725584024 | New‑Type Preheat Relay |
| 2 | ZQ150B0620 | Hexagon Head Bolt M6 |
| 3 | ZQ340B06 | Type 1 Hexagonal Nut M6 |
| 4 | YZ960077090040 | C7 Preheat Chassis Harness (240 Single‑layer Box Left 1700/M6/Seven‑circuit Fuse Box/Waterproof Relay) |
The New‑Type Preheat Relay is a high‑performance electromagnetic switch designed to handle the heavy current required by the engine’s glow plugs or intake air heater. It features silver‑alloy contacts that resist pitting and welding, and a sealed coil that prevents moisture ingress. This relay is rated for 150A continuous duty and is activated by the engine ECU, providing precise timing for optimal cold‑starting performance. As part of the Heating the Chassis Wiring Harness, it ensures that the preheat circuit receives full battery voltage with minimal drop, even in sub‑zero temperatures.
The Hexagon Head Bolt M6 is a high‑strength fastener used to securely mount the preheat relay and other components of the Heating the Chassis Wiring Harness. It is manufactured from grade 8.8 steel with a zinc‑plated finish to resist corrosion. The bolt’s hexagonal head allows for easy torquing with standard tools, ensuring a reliable and vibration‑proof connection.
The Type 1 Hexagonal Nut M6 is the matching nut for the M6 bolt, providing a secure clamping force. It is made from the same high‑strength steel and features a standard metric thread. This nut is used in conjunction with the bolt to secure the relay bracket and other mounting points within the Heating the Chassis Wiring Harness assembly, ensuring all components remain firmly in place under engine vibration.
The C7 Preheat Chassis Harness is the central wiring assembly that connects the preheat relay, battery, and glow plugs. It is specifically designed for the C7H with a 240Ah single‑layer battery box located on the left side, with a length of 1700mm to reach the engine bay. The harness includes all necessary conductors (M6 gauge), a seven‑circuit fuse box for individual circuit protection, and a waterproof relay housing to protect against moisture. This harness is the backbone of the Heating the Chassis Wiring Harness system, delivering power to the preheat elements exactly when needed.
Our Heating the Chassis Wiring Harness is manufactured to Sinotruk’s original specifications, guaranteeing exact fitment and connector compatibility with the C7H electrical architecture. The harness lengths and terminal types are precisely matched to the vehicle’s layout.
The new‑type relay and heavy‑gauge harness ensure that the glow plugs receive full power, reducing cranking time and preventing excessive starter wear. This Heating the Chassis Wiring Harness is essential for trucks operating in harsh winter climates.
We supply all necessary bolts, nuts, and the preheat chassis harness in one kit. No additional parts are required for installation, simplifying the replacement process and reducing workshop time.
The relay is sealed to IP67, and the harness is wrapped in high‑temperature loom tape, protecting against moisture, salt, and engine heat. The Heating the Chassis Wiring Harness is built to last the lifetime of the vehicle.
The Heating the Chassis Wiring Harness is a vital component for any Sitrak C7H that operates in cold environments. It ensures that the engine’s preheat system functions correctly, allowing for quick starts and reducing emissions during warm‑up. This harness connects the battery, relay, and glow plugs in a protected, organised manner.
The new‑type preheat relay is a significant improvement over older designs, featuring a higher contact pressure and faster switching time. This reduces the arcing that can degrade contacts over time, ensuring that the relay remains reliable for many seasons.
The C7 Preheat Chassis Harness is designed with the specific battery box configuration in mind – a 240Ah single‑layer box on the left side, requiring a 1700mm cable run. The harness includes a seven‑circuit fuse box that protects each preheat circuit individually, preventing a single short from disabling the entire system.
The harness is terminated with waterproof connectors that mate directly with the glow plug harness and the relay socket. This ensures a secure, corrosion‑free connection that withstands the harsh under‑hood environment.
Over time, the original relay contacts can become burnt or the harness insulation can crack, leading to high resistance and poor preheat performance. Replacing the entire Heating the Chassis Wiring Harness with our genuine kit restores the system to factory‑fresh condition, eliminating starting difficulties.
Installation is simple: mount the relay using the supplied M6 bolts and nuts, connect the chassis harness to the relay and battery positive terminal, and plug the harness into the existing glow plug circuit. The seven‑circuit fuse box provides easy access for fuse replacement.
We recommend performing a voltage drop test across the relay contacts after installation to verify that the Heating the Chassis Wiring Harness is delivering full battery voltage to the glow plugs. A drop of less than 0.2V is considered acceptable.
For fleet operators, standardising on this genuine Heating the Chassis Wiring Harness simplifies spare parts management and ensures consistent cold‑starting performance across all trucks. The robust construction reduces the frequency of replacements.
The relay coil is designed to operate on 12V or 24V systems, making it compatible with both standard and heavy‑duty electrical architectures. It includes a flyback diode to suppress voltage spikes, protecting the ECU.
The harness is wrapped in a flexible, heat‑resistant loom that also provides abrasion protection. This prevents short circuits caused by chafing against sharp edges in the engine bay.
We back our Heating the Chassis Wiring Harness with a 12‑month warranty against manufacturing defects. Our technical support team is available to assist with any installation queries.
We ship worldwide with tracking. Expedited shipping is available for urgent orders. Use the Send Email or Get Quotation buttons to request a personalised quote.
Choosing genuine Heating the Chassis Wiring Harness components ensures that your C7H starts reliably even on the coldest mornings. Aftermarket alternatives may not provide the same current capacity or durability.
We recommend periodic inspection of the harness and relay connections, especially before winter. Cleaning the terminals and ensuring they are tight will maximise performance.
The seven‑circuit fuse box is pre‑wired for the preheat circuits, but it also includes spare fuse slots for additional accessories, making it a versatile addition to the chassis electrical system.
The waterproof relay housing is designed to keep moisture out, even in high‑pressure washdown situations. This is essential for trucks that operate in wet or salty conditions.
We maintain a large inventory to ensure fast dispatch, even for bulk orders. Contact our sales team for volume pricing and customised logistics solutions.
Thank you for considering our Heating the Chassis Wiring Harness for your Sitrak C7H. We are confident that our genuine product will meet your expectations for quality and reliability.
The Heating the Chassis Wiring Harness is a critical component for cold‑weather operation. Investing in a genuine kit ensures that your truck starts every time, protecting your business from downtime.
We offer competitive pricing and fast shipping. Contact us today to order your Heating the Chassis Wiring Harness and ensure your truck is winter‑ready.
The preheat system is often overlooked until it fails. By proactively replacing the harness and relay with our genuine kit, you can avoid unexpected no‑start situations in freezing weather.
The Heating the Chassis Wiring Harness is a testament to Sinotruk’s commitment to quality and innovation, and we are proud to offer it to our customers.
Don’t settle for aftermarket substitutes that may compromise performance. Choose the genuine Heating the Chassis Wiring Harness and experience the difference that OEM quality makes.
Our online catalog provides comprehensive access to genuine SINOTRUK parts for all major vehicle lines — including HOWO, Sitrak, Steyr, and Yellow River series trucks. You can browse detailed specifications, original part numbers, and exploded-view diagrams for every assembly. Whether you are performing routine maintenance or planning a major overhaul, the catalog helps you quickly identify the correct components for your vehicle. When you become a SINOTRUK customer, we offer complimentary full‑access catalog services, ensuring you always have the latest product data and interchangeability information at your fingertips to support efficient fleet management and accurate parts ordering.
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