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- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1975-1977 3.0L Turbo (930)
Alternator 12V 75A – Internal Regulator
Restore dependable charging performance with this OEM
Supplier 12V 75A Alternator, equipped with an internal voltage regulator.
Manufactured by an Original Equipment supplier, this alternator is produced to
the same demanding standards as the component originally fitted by Porsche,
providing the quality, reliability and fitment expected from
factory-specification electrical components.
Fits:
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1983 3.3L Turbo (930)
The alternator is one of the most important components of the vehicle's electrical system. While the engine is running, it generates electricity to power essential systems including the ignition, lighting, fuel injection, instruments, heating and ventilation controls, whilst simultaneously recharging the battery. A failing alternator can quickly lead to a discharged battery, poor engine performance and complete electrical failure.
This unit is manufactured for precise fitment and dependable long-term operation, making it an ideal replacement for worn or failed original alternators during routine maintenance or restoration.
What Does the Alternator Do?
The alternator converts mechanical energy from the engine into electrical energy.
Its primary functions include:
- Charging the vehicle battery.
- Supplying electrical power whilst the engine is running.
- Maintaining a stable charging voltage.
- Supporting ignition and fuel systems.
- Powering lighting and electrical accessories.
- Preventing battery discharge during normal driving.
The internal voltage regulator continuously controls the alternator output, ensuring the battery and electrical components receive the correct charging voltage without overcharging.
Why Replace the Alternator?
Alternators are subjected to constant heat, vibration and high rotational speeds throughout their service life.
Common causes of failure include:
- Worn bearings.
- Failed internal voltage regulator.
- Worn brushes.
- Damaged slip rings.
- Internal winding faults.
- Diode pack failure.
- Corrosion.
- Age-related wear.
Replacing a worn alternator restores reliable charging performance and helps prevent unexpected breakdowns.
Symptoms of a Failing Alternator
Common signs include:
- Battery warning light illuminated.
- Battery repeatedly going flat.
- Slow engine cranking.
- Dim or flickering headlights.
- Unstable voltage.
- Electrical accessories operating poorly.
- Intermittent charging.
- Bearing noise from the alternator.
- Burning electrical smell in severe cases.
Ignoring these symptoms can eventually leave the vehicle unable to start once the battery becomes fully discharged.
Important Installation Information
This alternator is suitable for Porsche 911 models (1978-1983) using an internal voltage regulator.
For Porsche 911 turbo 3.0ltr (1975-1977) applications,
the following additional components are required:
- Resistor 91164198100
× 1
- Air Deflector 91110603305
× 1
- Cable Connector 111971511 × 2
Voltage: 12V
Power: 75 Amp.
Direction of rotation: Clockwise (CW)
Attachment: 6 bolts, Radius 135 mm
Controller: internal
Pulley: no
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91160312004
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 TURBO 2000-05
- 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 Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
Fits:
Porsche 986 Boxster 2003-2004
Porsche 987 Boxster 2005-2006
Porsche 987C Cayman 2005-2006
Porsche 996TT Turbo 2000-2005
Porsche 997 2005-2006
This alternator is fitted with freewheel pulley.
Plug type
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760301212
The product you are viewing cross references to these numbers
- 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
Fits:
For cars with Tiptronic transmission (I249) and Manual transmission (I480/481)
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
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760302205
The product you are viewing cross references to these numbers
- 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
Reconditioned alternator. For cars year 2007 onwards. (with Freewheel pulley)
Fits:
For cars with Tiptronic transmission (I249) and Manual transmission (I480/481)
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
Reconditioned Alternators are sold on a exchange basis, A surcharge of £100.00 will be held and then refunded when the old one is returned.
- The surcharge for this reconditioned part will be refunded when the exchange unit is received and approved by us and the relevant manufacturer.
- Please note, surcharge refunds often take an average of 6 to 8 weeks to be approved by the manufacturer.
- Acceptance of the exchange part is at the manufacturer's discretion, based on the part being fit for reconditioning.
- All surcharges and exchanges are subject to our terms and conditions.
PLEASE NOTE:
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760302205
The product you are viewing cross references to these numbers