Relays / Sensors / Resistors

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)

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.

Electric Air Conditioning Kit with Dual Condensers 

Transform the comfort and usability of your classic air-cooled Porsche 911 with this advanced Electric Air Conditioning Kit featuring a Dual Condenser System. Designed specifically for Porsche 911 models from 1974 to 1989, this revolutionary Electrocooler system completely re-engineers the factory air conditioning and ventilation setup using modern electric technology, significantly improving cooling performance, reliability and energy efficiency.

Unlike traditional belt-driven systems, the Electrocooler uses a compact electric compressor and modern HVAC components to deliver powerful cooling while dramatically reducing engine load. The result is a more comfortable cabin, improved performance and a significantly enhanced driving experience, even in extreme climates.

This dual condenser version is specifically designed for owners operating their vehicles in high-temperature and high-humidity environments, making it ideal for regions such as Florida, Singapore, the Middle East, Southern Europe and Australia.

A Complete Redesign of the Porsche 911 Air Conditioning System
The original air conditioning system fitted to many classic Porsche 911 models is often considered one of the weakest aspects of the car. Limited cooling performance, ageing components and inefficient airflow can make driving uncomfortable in warmer conditions.

The Electrocooler system addresses these shortcomings by delivering:

• Modern electric air conditioning technology
• Enhanced cooling performance
• Improved fresh air ventilation
• Upgraded heating air distribution
• Simplified operation
• Reduced engine load
• Improved cabin comfor
• Greater reliability

The result is a climate control system worthy of a modern sports car while maintaining the character of your classic Porsche.

Why Upgrade to Electric Air Conditioning?
Traditional engine-driven compressors consume significant engine power and add complexity to the engine bay.

The Electrocooler system offers numerous advantages:

Reduced Engine Load
The system typically uses less than 1 horsepower, helping preserve engine performance while improving fuel efficiency.

Lightweight Design
The complete system weighs approximately

• 35 lbs (16kg) complete system weight
• Lightweight narrow-wall hoses weighing under 4 lbs (1.5kg)

Modern Components
Every major component has been redesigned using modern technology for improved performance and reliability.

Cleaner Installation
The system fits within the front luggage compartment and utilises the factory fresh air vents to distribute cooled air, maintaining a clean and uncluttered cabin appearance.

Simple Operation
Control is managed through a single intelligent control button, providing straightforward operation and a factory-style user experience.

Dual Condenser System for Extreme Climates
This version incorporates a second condenser to maximise cooling performance in demanding environments.

Benefits include:

• Increased cooling capacity
• Improved refrigerant efficiency
• Better performance in high humidity
• Enhanced cooling during heavy traffic
• Superior cabin comfort in temperatures exceeding 35°C
• Reduced system workload

The additional condenser can be mounted within the left rear wing area, either ahead of or behind the rear wheel depending on installation requirements.

For vehicles operating in particularly hot climates, the dual condenser configuration is strongly recommended.

Installation Configuration
The system has been engineered specifically for Porsche 911 models and adapts to both left and right-hand drive vehicles.

Left-Hand Drive Vehicles
Compressor mounted within the smugglers box

Right-Hand Drive Vehicles
Compressor mounted ahead of the fuel tank

This approach ensures efficient packaging while maintaining practicality and serviceability.

Included Components
The kit contains:

• Electric A/C compressor and control ECU.
• Condenser, fan and shroud assembly.
• Replacement blower unit, housing modern fan and evaporator.
• Lightweight narrow wall hose set with custom fittings.
• ECU wiring loom and sundries.

We don’t provide:

• 60mm / 40mm air ducting (we recommend genuine Webasto aluminium/paper hose)
• Duct clips.  A selection of 60mm and 40mm is advisable.  We like the Porsche ones
• Rubber grommets (for routing hoses and wiring)
• ‘Oetiker’ crimp pliers / pincers
• Replacement washer bottle but we do have a kit available for the Boxster/996 bottle.

Tools and sundries needed:

• Good quality set of allen keys
• Standard wrenches and socket set.
• Side cutters
• Small selection of male and female spade terminals (6.8mm)
• Crimp tool for above
• Selection of cable ties ( 300mm) for general use
• Hose cutters
• Sharp knife (for cutting duct)

More information found in the attached PDF and YouTube video

Generation 2 Blower System
All kits now include the latest Generation 2 blower assembly featuring:

• Modern double-cage blower design
• Increased airflow capacity
• Improved efficiency
• Reduced noise levels
• Enhanced cooling distribution

The upgraded blower also improves fresh air circulation and heating performance.

Important Installation Information
Although the physical installation can be completed by competent enthusiasts, final commissioning should always be undertaken by a qualified air conditioning engineer.

Professional installation is recommended for:

• Hose crimping
• Pressure testing
• Refrigerant filling Leak testing
• System commissioning

For safety and reliability reasons, refrigerant charging using consumer R134a refill cans is not recommended.

Additional Recommendations
Because the electric compressor requires a healthy electrical supply, upgrading the original alternator is recommended for the majority of installations.

This helps ensure:

• Reliable system operation
• Stable voltage supply
• Improved electrical performance
• Long-term system reliability       

Electric Air Conditioning Kit with Single Condenser 

Transform the comfort and usability of your classic air-cooled Porsche 911 with this advanced Electric Air Conditioning Kit featuring a Single Condenser System. Designed specifically for Porsche 911 models from 1974 to 1989, this revolutionary Electrocooler system completely re-engineers the factory air conditioning and ventilation setup using modern electric technology, significantly improving cooling performance, reliability and energy efficiency.

Unlike traditional belt-driven systems, the Electrocooler uses a compact electric compressor and modern HVAC components to deliver powerful cooling while dramatically reducing engine load. The result is a more comfortable cabin, improved performance and a significantly enhanced driving experience, even in extreme climates.

This dual condenser version is specifically designed for owners operating their vehicles in high-temperature and high-humidity environments, making it ideal for regions such as Florida, Singapore, the Middle East, Southern Europe and Australia.

A Complete Redesign of the Porsche 911 Air Conditioning System
The original air conditioning system fitted to many classic Porsche 911 models is often considered one of the weakest aspects of the car. Limited cooling performance, ageing components and inefficient airflow can make driving uncomfortable in warmer conditions.

The Electrocooler system addresses these shortcomings by delivering:

• Modern electric air conditioning technology
• Enhanced cooling performance
• Improved fresh air ventilation
• Upgraded heating air distribution
• Simplified operation
• Reduced engine load
• Improved cabin comfor
• Greater reliability

The result is a climate control system worthy of a modern sports car while maintaining the character of your classic Porsche.

Why Upgrade to Electric Air Conditioning?
Traditional engine-driven compressors consume significant engine power and add complexity to the engine bay.

The Electrocooler system offers numerous advantages:

Reduced Engine Load
The system typically uses less than 1 horsepower, helping preserve engine performance while improving fuel efficiency.

Lightweight Design
The complete system weighs approximately

• 35lbs (16kg) complete system weight
• Lightweight narrow-wall hoses weighing under 4lbs (1.5kg)

Modern Components
Every major component has been redesigned using modern technology for improved performance and reliability.

Cleaner Installation
The system fits within the front luggage compartment and utilises the factory fresh air vents to distribute cooled air, maintaining a clean and uncluttered cabin appearance.

Simple Operation
Control is managed through a single intelligent control button, providing straightforward operation and a factory-style user experience.

Dual Condenser System for Extreme Climates
This version incorporates a second condenser to maximise cooling performance in demanding environments.

Benefits include:

• Increased cooling capacity
• Improved refrigerant efficiency
• Better performance in high humidity
• Enhanced cooling during heavy traffic
• Superior cabin comfort in temperatures exceeding 35°C
• Reduced system workload

The additional condenser can be mounted within the left rear wing area, either ahead of or behind the rear wheel depending on installation requirements.

For vehicles operating in particularly hot climates, the dual condenser configuration is strongly recommended.

Installation Configuration
The system has been engineered specifically for Porsche 911 models and adapts to both left and right-hand drive vehicles.

Left-Hand Drive Vehicles
Compressor mounted within the smugglers box

Right-Hand Drive Vehicles
Compressor mounted ahead of the fuel tank

This approach ensures efficient packaging while maintaining practicality and serviceability.

Included Components
The kit contains:

• Electric A/C compressor and control ECU.
• Condenser, fan and shroud assembly.
• Replacement blower unit, housing modern fan and evaporator.
• Lightweight narrow wall hose set with custom fittings.
• ECU wiring loom and sundries.

We don’t provide:

• 60mm / 40mm air ducting (we recommend genuine Webasto aluminium/paper hose)
• Duct clips.  A selection of 60mm and 40mm is advisable.  We like the Porsche ones
• Rubber grommets (for routing hoses and wiring)
• ‘Oetiker’ crimp pliers / pincers
• Replacement washer bottle but we do have a kit available for the Boxster/996 bottle.

Tools and sundries needed:

• Good quality set of allen keys
• Standard wrenches and socket set.
• Side cutters
• Small selection of male and female spade terminals (6.8mm)Crimp tool for above
• Selection of cable ties ( 300mm) for general use
• Hose cutters
• Sharp knife (for cutting duct)

More information found in the attached PDF and YouTube video

Generation 2 Blower System
All kits now include the latest Generation 2 blower assembly featuring:

• Modern double-cage blower design
• Increased airflow capacity
• Improved efficiency
• Reduced noise levels
• Enhanced cooling distribution

The upgraded blower also improves fresh air circulation and heating performance.

Important Installation Information
Although the physical installation can be completed by competent enthusiasts, final commissioning should always be undertaken by a qualified air conditioning engineer.

Professional installation is recommended for:

• Hose crimping
• Pressure testing
• Refrigerant filling
• Leak testing
• System commissioning

For safety and reliability reasons, refrigerant charging using consumer R134a refill cans is not recommended.

Additional Recommendations
Because the electric compressor requires a healthy electrical supply, upgrading the original alternator is recommended for the majority of installations.

This helps ensure:

• Reliable system operation
• Stable voltage supply
• Improved electrical performance
• Long-term system reliability