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Wiring harness
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05

Fits:
Porsche 996 C4S 2002-05
Porsche 996 Turbo 2001-05
Click 'Zoom in' for large parts diagram.
Diagram ref no 2
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99663143701
The product you are viewing cross references to these numbers
Wiring Harnesses – Precision Electrical Connectivity for Porsche Vehicles
Wiring harnesses are the backbone of your Porsche’s electrical system. They connect and deliver power between critical components - from lighting and sensors to engine management and infotainment systems - ensuring everything functions as designed. A properly fitted harness guarantees reliable electrical performance, signal integrity, and safety throughout the vehicle.
At Design911, we supply a wide range of genuine and high-quality wiring harnesses for Porsche models including 911, Boxster, Cayman, Cayenne, Macan, and Panamera. Each harness is meticulously engineered offering precision, reliability, and durability as intended
What Do Wiring Harnesses Do?
A wiring harness is a complex assembly of wires, connectors,
and terminals designed to:
- Transmit
power and data between electrical systems.
- Protect
electrical circuits with insulated, organised routing.
- Simplify
installation and maintenance by combining multiple wires into one
unified assembly.
- Ensure correct communication between sensors, ECUs, lights, and other modules.
In modern Porsches, wiring harnesses play a vital role in enabling advanced technologies — from adaptive lighting and traction control to comfort and entertainment systems.
Why Do Wiring Harnesses Fail?
Even though designed for longevity, wiring harnesses can
degrade or fail due to:
- Heat
exposure or engine vibration causing insulation wear.
- Moisture
ingress or corrosion in connectors and terminals.
- Rodent
damage or physical abrasion from engine movement.
- Electrical
overloads or short circuits damaging internal wiring.
- Previous repairs or poor modifications affecting performance.
Signs of a failing wiring harness include flickering lights, intermittent electrical faults, dashboard warnings, or complete system failure.
Why Replace Faulty Wiring Harnesses?
Replacing a damaged wiring harness restores proper electrical performance, eliminates intermittent issues, and prevents costly damage to control modules or sensors.
Benefits of replacement include:
- Restored power delivery and communication across systems.
- Improved reliability and protection against shorts or fires.
- Elimination of diagnostic faults and warning lights.
- Precision-fit installation with manufacturer-standard components.
Each harness in this range is built using high-grade materials and connectors, ensuring accurate fitment, corrosion resistance, and long-term dependability.
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Fuel Pumps
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Brake & Clutch Switch
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Handbrake Switch
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Reverse Light Switch
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Headlamp Switch
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Window Switch
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Window Motors
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Window Mechanism
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Wiper Motor
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Wiper Mechanism
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Electric Horn
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SmartTop Control Units
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Ignition Switch
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Indicator / Wiper Stalk Switch
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Roof / Sun Roof Switch
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Relays / Fuses
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Washer pumps / bottles / jets
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Alarms / Security / Central Locking
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Electronic Control Units
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Wiper Switches
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Dashboard / Console Parts & Switches
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Door Mirror Switch
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Phone Kits / Bluetooth / Ipod
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Bonnet / Rear Lid / Spoiler Activators & Motors
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Air Bags & Parts
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Tracker
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Connector housing
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