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Relays / Sensors / Resistors
By OE Match
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
Air Conditioning Relay
Restore reliable operation of your Porsche air conditioning
system with this OE Match Air Conditioning Relay for Porsche 911 models from
1974 to 1988. Designed to OE specifications, this essential electrical
component controls power delivery within the air conditioning system, ensuring
the compressor, blower and associated components operate correctly when cooling
is required.
Fits:
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1988 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1988 3.3L Turbo (930)
* Please check and match the part number of your relay in your car before ordering.
Although small and often overlooked, the air conditioning relay plays a critical role in the operation of the vehicle's climate control system. A faulty relay can prevent the air conditioning system from functioning correctly, leading to intermittent cooling, compressor failure to engage or complete loss of A/C operation.
Manufactured to OE Match standards, this replacement relay provides dependable performance and factory-correct fitment for maintenance, fault diagnosis and restoration projects.
What Does the Air Conditioning Relay Do?
The air conditioning relay acts as an electrically controlled switch within the A/C system.
Its primary functions include:
- Controlling power to the air conditioning system
- Activating the compressor circuit
- Supporting blower motor operation
- Protecting electrical circuits
- Managing high-current loads safely
- Ensuring reliable A/C engagement
- Supporting climate control functionality
The relay allows low-current control circuits to safely operate higher-current air conditioning components.
Why Do Air Conditioning Relays Fail?
Like all electrical relays, air conditioning relays experience wear throughout their service life.
Common causes of failure include:
- Contact wear
- Heat-related deterioration
- Electrical arcing
- Internal corrosion
- Moisture ingress
- Age-related component fatigue
- Voltage fluctuations
- Extended periods of operation
Over time, relay contacts can become worn or contaminated, resulting in unreliable operation.
Symptoms of a Faulty Air Conditioning Relay
Common warning signs include:
- Air conditioning not switching on
- Compressor failing to engage
- Intermittent cooling performance
- Blower operation faults
- Clicking noises from the relay
- Unreliable climate control operation
- Electrical system fault diagnosis issues
- Complete A/C system inactivity
Because relay failures can mimic other air conditioning faults, they are often checked early during diagnosis.
When Should the Air Conditioning Relay Be Replaced?
Replacement is recommended when:
- Diagnosing air conditioning faults
- Compressor engagement becomes intermittent
- Air conditioning stops functioning
- Electrical testing identifies relay failure
- Restoring a Porsche 911
- Performing preventative maintenance
- Refurbishing the climate control system
Many specialists replace ageing relays during electrical restoration work to improve long-term reliability.
Why Replacement Matters
Replacing a failing relay can restore proper operation of the entire air conditioning system.
Benefits include:
- Reliable compressor engagement
- Consistent cooling performance
- Improved electrical reliability
- Reduced risk of intermittent faults
- Enhanced climate control operation
- Improved driving comfort
- Better diagnostic accuracy
- Long-term system dependability
For classic Porsche 911 models, maintaining reliable electrical components helps preserve both usability and originality.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91161510302
The product you are viewing cross references to these numbers
-
electrical components for air conditioner 911 1978-83 813-40
-
electrical components for air conditioner 911 1987-89 813-40
-
electrical components for air conditioner 911 1984-86 813-40
-
air conditioner evaporator housing complete with air duct not for (USA) 911 1970-73 813-50
-
Air conditioner electrical components accessories not for (USA) 911 1970-73 813-70
-
ventilation heating 911 upto 1968 813-00
-
blower for Left-Hand Drive cars for 911 S, 911 /TU/L and 912 (USA) UPTO 1968 813-05
-
mounting plate 911 1965-69 901-10
-
horn relay 911 1965-69 903-15
-
Air conditioner, electrical components 911 1974-77 813-50
-
air conditioner, electrical components 911 TURBO 1975-77 813-50
OEMatch relays, sensors and resistors for Porsche models help regulate blower motors, temperature control and other electrical functions within climate and auxiliary systems. These components manage electrical flow, monitor conditions and adjust motor speeds to keep cabin systems responsive. OEMatch relays, sensors and resistors are compatible replacements engineered to original-spec dimensions and tolerances — a practical option when genuine or OEM parts are unavailable.
Available Types- HVAC relays for fan and compressor control
- Blower motor resistors and resistor packs
- Cabin temperature, ambient and evaporator sensors
- Pressure and switch sensors for system monitoring
OEM (Original Equipment Manufacturer) parts are made by the same company that produced your Porsche’s original relays, sensors and resistors.
OE (Original Equipment) refers to parts matching original specifications for the relays, sensors and resistors and may be supplied by alternative manufacturers. Aftermarket parts offer alternative options, sometimes with enhanced features or better value. OEMatch supplies non-OEM relays, sensors and resistors engineered as direct-fit alternatives to OEM parts, made to original-spec dimensions and tolerances for Porsche models.
Relays, sensors and resistors control electrical power, provide feedback on temperature and pressure, and regulate motor speeds. Failures commonly result in intermittent fan operation, incorrect cabin temperature readings or complete loss of heating and cooling. OEMatch supplies a broad selection of Porsche-focussed parts and continues to develop new lines to support climate and electrical system repairs across model generations.
Benefits Include- Restores accurate fan and temperature control for consistent cabin comfort
- Reduces risk of electrical faults that can lead to blown fuses or motor damage
- Aids diagnostic accuracy when troubleshooting HVAC and electrical systems
- Corrosion or oxidation on terminals and connectors impeding electrical contact
- Overheating or short circuits from electrical surges damaging components
- Moisture ingress, condensation or environmental contamination
- Age-related sensor drift and resistors burning out under sustained load
Replacing worn relays, sensors and resistors restores accurate climate control, prevents secondary electrical damage and reduces the chance of intermittent faults that affect comfort and system reliability in Porsche models. Timely replacement supports correct diagnostics, avoids unnecessary component changes and helps maintain consistent operation of related systems.
Advantages- Manufactured to original-spec dimensions to fit factory mounting and connectors
- Designed for thermal and vibration resilience typical of vehicle environments
- Can be fitted using standard procedures; follow model-specific guidance for torque and reconnection checks
