do not press the back button…
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
Ignition Switch
By OE Match
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche Carrera GT 2003-06
The OE MATCH Ignition Starter Switch is an original equipment-style replacement electrical component designed for selected Porsche Boxster (986), Porsche 911 (996) and Porsche Carrera GT models.
Fits:- Porsche 986 Boxster 2004>>
- Porsche 996 2004>>
- Porsche 996 Turbo 2004>>
- Porsche 996 GT3 2004>>
- Porsche Carrera GT 2004>
Diagram Ref No 22
Installed as part of the ignition lock assembly, this switch converts the mechanical movement of the ignition key into the electrical switching actions required to activate the vehicle's ignition circuits and initiate engine starting.
The ignition starter switch is an essential part of the vehicle's electrical system. When the driver turns the key, the switch operates the appropriate electrical contacts to supply power to the relevant ignition and accessory circuits and send the starting signal to the starter control system.
A properly functioning ignition switch ensures that the vehicle's electrical systems respond correctly to the selected key position and that the starter motor can be engaged when the driver attempts to start the engine.
The OE MATCH 4B0905849/1 is designed to replace the corresponding original switch, restoring the intended electrical connections and operation without modifying the factory wiring arrangement.
Over time, ignition starter switches can deteriorate due to repeated key operation, electrical contact wear, heat and ageing of internal components.
The electrical contacts may become worn, contaminated or unreliable, resulting in intermittent starting problems, failure of certain electrical accessories or unexpected interruptions to ignition-controlled circuits.
A defective ignition starter switch can cause the engine to fail to crank even when the battery and starter motor are functioning correctly. In some cases, electrical systems may operate inconsistently or lose power when the ignition key is moved between positions.
Replacing a faulty switch with the OE MATCH Ignition Starter Switch 4B0905849/1 helps restore reliable electrical contact, consistent ignition operation and dependable engine starting.
What This Product Does:
The ignition starter switch is the electrical switching component operated by the vehicle's ignition lock mechanism.
Its primary functions include:
- Activates the Ignition Circuits: Supplies electrical power to the appropriate vehicle systems when the ignition is switched on.
- Initiates Engine Starting: Sends the electrical starting signal to the starter control circuit when the key is turned to the start position.
- Controls Accessory Power: Switches the relevant accessory circuits according to the ignition key position.
- Supports Dashboard Electrical Operation: Helps provide the ignition-switched power required by associated instruments and vehicle systems.
- Maintains Correct Key-Position Switching: Ensures the corresponding electrical circuits are activated or deactivated as the key moves between positions.
- Works with the Ignition Lock Assembly: Converts mechanical key movement into electrical switching actions.
- Supports Reliable Engine Starting: Provides the electrical connection needed to initiate the starting sequence.
- Maintains Electrical Circuit Control: Helps distribute power to the appropriate ignition-controlled systems.
- Supports Normal Engine Operation: Maintains electrical supply to relevant ignition-switched circuits while the vehicle is running.
- Preserves Original Equipment Functionality: Restores the factory electrical ignition-switch arrangement.
Symptoms Of Wear Or Failure:
The ignition starter switch is operated every time the vehicle is started or switched off.
Repeated use, electrical loading and age-related deterioration can cause internal contacts or mechanical interfaces to wear.
Common symptoms of a failing ignition starter switch include:
- Engine Fails to Crank: Turning the ignition key to the start position produces no starter motor response.
- Intermittent Starting Problems: The engine starts normally on some occasions but fails to crank on others.
- Key Turns but Nothing Happens: The ignition key moves through its normal positions, but the expected electrical response is absent.
- Repeated Attempts Needed to Start: The driver may need to turn the key several times before the starter circuit responds.
- Loss of Accessory Power: Certain ignition-controlled accessories may fail to operate correctly.
- Intermittent Dashboard Power: Instrument panel warning lights or displays may behave inconsistently when the ignition is switched on.
- Electrical Systems Operating Erratically: Ignition-switched components may turn off unexpectedly or operate intermittently.
- Engine Cutting Out: A severe loss of ignition-switched electrical power may contribute to unexpected engine shutdown.
- Starter Not Engaging Consistently: Worn start-position contacts may interrupt the signal required to operate the starter system.
- Electrical Functions Remaining Active: A switch that fails to change state correctly may leave certain circuits powered when they should be off.
- Unusual Resistance During Key Operation: Damage within the switch or its mechanical drive may affect the feel of the ignition mechanism.
- Intermittent Contact When the Key Is Moved: Electrical systems may briefly activate or deactivate when the key position changes slightly.
- Heat-Damaged Electrical Connections: Overheating or high resistance may cause discolouration or damage around the connector.
- Complete Ignition Switch Failure: The switch may stop supplying power to the expected ignition circuits.
Why Replacement Matters:
Replacing a worn or defective ignition starter switch is important for restoring dependable engine starting and reliable operation of the vehicle's ignition-controlled electrical systems.
- Restores Reliable Engine Starting: Helps correct starting problems caused by defective internal switch contacts.
- Improves Electrical Contact: Replaces worn or unreliable electrical switching components.
- Reduces Intermittent Starting Faults: Helps eliminate inconsistent starter engagement where the switch is responsible.
- Maintains Ignition Circuit Power: Supports continuous power delivery to the relevant ignition-switched systems.
- Restores Accessory Circuit Operation: Helps correct electrical faults caused by defective accessory-position contacts.
- Improves Electrical Reliability: Maintains the intended switching sequence between ignition key positions.
- Reduces the Risk of Unexpected No-Start Conditions: Replaces a deteriorating component before it fails completely.
- Supports Dependable Vehicle Operation: Helps prevent interruptions to ignition-controlled circuits.
- Maintains Factory Wiring Compatibility: Designed for the corresponding original Porsche electrical connection arrangement.
- Original Equipment-Style Fitment: Provides a replacement for the specified factory ignition switch.
- Supports Effective Fault Repair: Allows a diagnosed electrical ignition switch failure to be repaired without replacing unrelated components.
- Ideal for Preventative Maintenance: Suitable when the original switch shows clear evidence of wear or intermittent operation.
- Cost-Effective Replacement: May resolve starting or electrical problems without requiring replacement of the entire ignition lock assembly.
- Supports Porsche Electrical System Maintenance: Helps preserve reliable operation of an important vehicle control system.
The ignition starter switch is a relatively small electrical component, but its operation is essential for normal vehicle use.
A worn switch may initially produce occasional starting difficulties or intermittent accessory faults. As the electrical contacts continue to deteriorate, the problem may become more frequent.
Eventually, the vehicle may fail to crank or certain ignition-switched systems may stop functioning correctly.
Where the switch is responsible for an interruption to ignition power, continued deterioration may also affect the vehicle while it is running.
Replacing a confirmed defective switch with the OE MATCH 4B0905849/1 helps restore the correct electrical switching functions and reduce the likelihood of further ignition-related problems.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
4B0905849
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
The OE MATCH Ignition Starter Switch is a electrical component designed to control the vehicle’s ignition and starter system. Installed behind the ignition lock barrel, the switch transfers the driver’s key input into electrical signals that activate the vehicle’s accessory circuits, ignition system, and starter motor.
Fits:
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
Diagram Ref No 22
This OE MATCH ignition starter switch is engineered to provide reliable electrical contact, smooth operation, and direct-fit compatibility with the original wiring system. It plays a vital role in vehicle starting, power distribution, and overall electrical system functionality.
What This Product Does:
- Activates the vehicle ignition system when the key is turned
- Controls power delivery to accessory and ignition circuits
- Engages the starter motor to start the engine
- Distributes electrical power to key vehicle systems
- Works in conjunction with the ignition lock assembly
- Ensures reliable vehicle starting and operation
Symptoms Of Wear Or Failure:
- Engine fails to crank when the key is turned
- Intermittent starting problems
- Loss of power to ignition or accessory circuits
- Dashboard warning lights behaving erratically
- Key turning normally but no starter engagement
- Vehicle stalling due to ignition power interruption
- Electrical accessories failing to operate correctly
- Burnt contacts causing inconsistent electrical connections
Why Replacement Matters:
- Restores dependable engine starting functionality
- Ensures proper power distribution to ignition and accessory systems
- Prevents intermittent starting and electrical faults
- Maintains consistent communication between the key and vehicle systems
- Reduces the risk of unexpected breakdowns
- Supports safe and reliable vehicle operation
- Provides OE-style fitment and performance
- Helps preserve the integrity of the vehicle’s electrical and starting systems
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
4A0905849B
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
Ignition Problem Symptoms:
- Car won't start
- Tough to start
- Key gets stuck in ignition
- Key sticking in tumbler
Fits: RHD or LHD CARS
Fits:
Porsche Boxster 986
Porsche 996 up to 2004
Diagram Ref No. 20
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99634701707
The product you are viewing cross references to these numbers
OEMatch Ignition Switch — Fit, Function, Confidence
Ignition switches control the electrical stages required to start and run a Porsche. This collection covers mechanical and electronic ignition switches, barrels and lock sets chosen for Porsche models to restore starter and accessory power and to reduce intermittent electrical faults caused by worn contacts or cylinders.
Available Types
- Mechanical ignition barrels and key cylinders
- Electronic start switches and sensor-integrated modules
- Ignition lock sets and housings
- Replacement tumblers and barrels
Understanding OEMatch Ignition Switch
OEM (Original Equipment Manufacturer) parts are made by the same company that produced your Porsche’s original ignition switch. OE (Original Equipment) refers to parts matching original specifications for the ignition switch and may be supplied by alternative manufacturers. Aftermarket parts offer alternative options, sometimes with enhanced features or better value. OEMatch supplies non-OEM ignition switches engineered as direct-fit alternatives to OEM parts, made to original-spec dimensions and tolerances for Porsche models.
The ignition switch routes power through accessory, on and start positions to feed systems such as the starter motor, fuel pump and dashboard electronics. In modern Porsche models the switch may also interact with immobiliser systems or electronic control modules, so correct electrical and mechanical interfaces are important for reliable operation.
Benefits Include
- Restored starter operation and consistent engine cranking
- Elimination of intermittent accessory and instrument faults
- Correct power sequencing for electrical systems
Why Ignition Switch Wear and Fail
- Worn electrical contacts leading to intermittent or no power
- Key cylinder wear causing stiffness or sticking when turning
- Corrosion or heat-related internal short circuits
The Importance of Replacing with OEMatch Ignition Switch
Replacing a worn ignition switch reduces the risk of a breakdown and restores predictable electrical control. Choosing an OEMatch ignition switch helps retain correct mounting and electrical interfaces for Porsche models while addressing common causes of failure.
Advantages
- Designed to match original-spec dimensions for consistent operation
- Compatible with original mounting points and electrical interfaces where specified
- Options for mechanical and electronic assemblies to suit different model requirements
Support & Advice
These items affect safety-critical systems. Installation should be carried out by a qualified technician following model-specific procedures and torque settings. Use calibrated tools and new fasteners where specified.
