Dongfeng KL truck parts Left door wiring harness assembly 3724050-C3301

Built as the “nerve network” of the left door, this harness features precision-engineered wiring to guarantee fast, interference-free signal and power transmission. It uses high-purity oxygen-free copper (OFC) conductors with cross-sectional areas ranging from 0.3mm² (sensor signals) to 2.5mm² (window motor power), achieving conductivity ≥98% IACS and voltage drop ≤0.06V/m. Signal wires for sensitive components (e.g., mirror position sensors) are twisted in pairs (twist pitch 20mm) and shielded with aluminum foil + tinned copper braid, reducing electromagnetic interference (EMI) by 75% to prevent erratic window movement or lock failures. Power circuits integrate dedicated fuses (10-15A) to avoid overloading, while the harness’s branch design follows the left door’s internal contour, eliminating redundant wiring and ensuring efficient current flow

Engineered to withstand 100,000+ door opening/closing cycles, the 3724050-C3301 harness features a flexible, wear-resistant structure optimized for dynamic stress. The critical section connecting the door to the cab uses a spiral-wound nylon protective tube with a flexible rubber core, allowing ±90° bending without wire fatigue or breakage. Wires are insulated with thermoplastic elastomer (TPE) instead of rigid PVC—this material remains pliable in temperatures from -40℃ to 125℃, avoiding brittleness in frigid winters that causes insulation cracking. The harness is secured with vibration-absorbing nylon cable ties (spaced 250mm apart) that prevent abrasion against metal door components, while reinforced strain relief at connector ends distributes stress during door movement, avoiding terminal pull-out

Optimized to endure the harsh conditions of truck doors (exposed to rain, dust, diesel fumes, and road salt), the harness integrates comprehensive protective measures. All connectors are IP67-rated, with HNBR rubber seals that form a water-tight barrier—passing 1200-hour neutral salt spray testing (ASTM B117) with no corrosion. The main harness is wrapped in a double-layer shield: an inner polyester braid (density 18×18 strands/cm²) for abrasion resistance and an outer UV-stabilized sleeve to prevent sun-induced degradation. Terminals are tin-plated (5μm thickness) and feature a locking design for secure contact, even during cab vibration (10-500Hz). The TPE insulation resists diesel fuel, cleaning agents, and oil, ensuring electrical integrity in construction, coastal, and snowy environments

This left door wiring harness is designed for efficient maintenance and long-term cost savings for Dongfeng KL operators. Pre-assembled connectors and color-coded, labeled branches (e.g., “Window Motor,” “Mirror Heater”) allow a single technician to complete replacement in 60 minutes—60% faster than custom-wired solutions. The OE-compatible design eliminates BCM communication errors common with aftermarket harnesses, which often cause non-functional doors and $400+ in diagnostic/repair costs. The high-durability components extend service life to ≥250,000km—three times that of cheap alternatives—reducing replacement frequency. By ensuring reliable operation of safety-critical features (e.g., power locks), it prevents security risks and driver downtime. Backed by a 2-year/200,000km Dongfeng warranty, it provides predictable maintenance expenses and enhances fleet productivity