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- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 2S 3.8L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche 997 MK1 Carrera 4S 3.8L 2005-08
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 / GT3 RS 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
As the heart of your charging system, this alternator supplies electrical power to all onboard systems and recharges the battery while the engine runs. It ensures reliable operation of lights, infotainment, climate control, and engine electronics under demanding loads.
Fits:
For cars with Tiptronic transmission (I249)
Porsche 987.1 Boxster 2007-08
Porsche 987C.1 Cayman 2007-08
Porsche 997.1 Carrera 2007-09
Porsche 997.1 Turbo 2007-09
Porsche 997 GT3 2010-11
Plug type
Diagram ref no 20
A failing alternator can cause low voltage, battery drain, flickering lights, or total electrical failure. Upgrading with an OE Match unit restores consistent charging performance and avoids costly roadside failures.
- Fits Porsche 911, Boxster, and Cayman models (verify engine compatibility)
- 150-amp output for stable electrical and charging performance
- Fixed-type pulley design for direct bolt-on installation
- Matches factory alternator dimensions, connections, and output curve
- Restores optimal charging to power all vehicle systems
- Built with high-quality bearings, windings, and voltage regulators for longevity
- Tested for durability and consistent voltage under high-load operation
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760302204
The product you are viewing cross references to these numbers
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
12 Volt 90 Amp Alternator
The Porsche Alternator is a high-quality 12 Volt
90 Amp charging system component designed for Porsche 911 and Porsche 911 turbo
models. As one of the most important electrical components on the vehicle, the
alternator generates electrical power while the engine is running and
continuously recharges the battery to maintain reliable operation of the
vehicle's electrical systems.
Fits:
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
From powering the ignition system and fuel delivery
components to supporting lighting, instrumentation, heating and other
electrical accessories, the alternator plays a crucial role in the day-to-day
reliability and performance of your Porsche. Without a properly functioning
alternator, the battery will gradually discharge, leading to starting
difficulties, electrical faults and eventually complete vehicle shutdown.
Overall length: 173mm
Voltage: 12V
Power: 90Amp
Direction of rotation: clockwise (CW)
Fixing: 6 studs
Controller: internal
Pulley: not supplied
Whether you're maintaining an air-cooled Porsche 911, servicing a Porsche 911 turbo or carrying out a restoration project, replacing a worn alternator helps ensure dependable performance and protects the vehicle's electrical system.
What Does an Alternator Do?
The alternator converts mechanical energy generated by the engine into electrical energy. Driven by the engine belt system, it supplies power to the vehicle while simultaneously charging the battery.
The alternator is responsible for:
Recharging the battery while driving Powering electrical systems and accessories Maintaining stable system voltage Supporting ignition and fuel system operation Ensuring reliable starting performanceA healthy alternator is essential for keeping every electrical system operating correctly.
Symptoms of Alternator Wear or Failure
Alternators operate continuously whenever the engine is running and are subjected to heat, vibration and electrical load. Over time, internal components such as bearings, brushes, voltage regulators and diodes can wear or fail.
Common symptoms of alternator failure include:
Battery warning light illuminated Repeated flat batteries Slow or difficult engine starting Flickering headlights Dimming dashboard lights Electrical accessories operating intermittently Low charging voltage Unusual whining or grinding noises Burning electrical smell Vehicle stalling due to insufficient voltageIn many cases, alternator failure develops gradually before progressing to complete charging system failure.
Why Alternator Replacement Matters
A faulty alternator can leave the battery unable to recharge properly, eventually causing loss of electrical power and unexpected breakdowns.
Replacing a worn alternator helps:
Restore correct battery charging Improve electrical system reliability Prevent roadside breakdowns Maintain stable voltage output Extend battery life Protect sensitive electrical components Eliminate charging system warning lights Improve overall vehicle dependabilityFor classic and performance Porsche models, maintaining a healthy charging system is essential for reliable operation and long-term ownership enjoyment.
Features & Benefits
- 12 Volt, 90 Amp output
- Provides reliable battery charging
- Maintains stable electrical system voltage
- Supports ignition and fuel system operation
- Durable construction for long service life
- Ideal for maintenance, repairs and restoration projects
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91160312005
The product you are viewing cross references to these numbers
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 914 (1970-1976)
Fits:
Porsche 911 3.2 Carrera - 1984 to 1989
Porsche 911 turbo - 1984 to 1989
The air deflector serves as an air baffle and provides optimal cooling of the cylinders. Bolts to the back of the alternator.
Diagram ref no 10
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91110605502
The product you are viewing cross references to these numbers