Relays play a crucial role in automotive air conditioning systems by precisely switching high-current circuits using low-current signals. This guide highlights five reliable car AC relays that are well-suited for controlling compressors and related components. Each product is evaluated for durability, electrical suitability, and practical use across common vehicle models. Readers will find considerations for selecting the right relay, along with a buying guide that compares sealing, coil voltage, current rating, and installation needs.
| Product | Brand | Coil Voltage | Current Rating |
|---|---|---|---|
| Yourkar 2 PCS Car AC Relay | Yourkar | 12VDC | Not stated (suitable for AC/compressor control) |
| Ohleats 2PCS Car AC Relay | Ohleats | 12VDC | Not stated (useful for high-current automotive circuits) |
| Zlirfy 2 Pack AC Relay | Qziulr | 12VDC | 35A rated (per coil/relay data) |
| ACDelco GM Original Equipment 13500114 | GM GENUINE PARTS | 12VDC | Not stated (GM OE replacement) |
| KVAEY 2 PCS Car AC Relay | KVAEY | 12VDC | 25A max |
Yourkar 2 PCS Car AC Relay
The Yourkar relay kit offers practical on-off control suitable for automotive AC systems. It converts low voltage signals into high-current control signals to actuate the compressor circuit. The relays are designed to resist environmental exposure, enhancing longevity in vehicle environments. These relays support precise switching, contributing to reliable compressor operation and fan control. The build emphasizes corrosion resistance and stable electrical connections for extended use in varied climates.
BOJACK 1 Poles FLA 40 Amp Coil 24 VAC Contactor
This discrete contactor-style relay is designed for higher current loads and can be suitable for compressor circuits in some setups. The 40-amp rating aligns with typical automotive AC condenser or condenser fan control requirements in several applications. It offers straightforward installation with a single pole configuration, delivering decisive switching for heavy-duty automotive electrical control while maintaining reliability under automotive heat and vibration.
Ohleats 2PCS Car AC Relay
Ohleats provides a versatile relay compatible with several OEM-style relay numbers, including 39794-SDA-A03 and G8HL-H71. This makes it a practical option for a variety of vehicle makes and models, including common Honda and Acura configurations. Its function centers on controlling high-current lines with low-current triggers, enabling reliable motor or compressor engagement while offering protections like fast response and resistance to high temperatures.
Zlirfy 2 Pack AC Relay
The Zlirfy (Qziulr listing) relay set emphasizes standard 12V coil operation with a 35A contact rating, making it suitable for many automotive AC tasks, including fan and compressor control. It references commonly used OEM part numbers like 39794-SDA-A03 and 39794-SDA-A05, aiding compatibility with a range of vehicle systems. The relays offer durability and reliable performance in typical driving conditions, supporting consistent switching with moderate energy use.
ACDelco GM Original Equipment 13500114
The GM Original Equipment relay is presented as a GM OE replacement part, aligning with GM vehicle specifications for fit, form, and function. This makes it a solid choice for owners seeking a direct compatibility option that aligns with factory performance expectations. The product emphasizes reliability, durability, and consistent operation, contributing to stable compressor and auxiliary circuit control in GM vehicles.
Aeola 4 Pack AC Relay 39794-SDA-A03
The Aeola set references multiple compatible OEM numbers, offering a compact low-profile design suitable for PCB mounting with relatively low heat. The 4-pin configuration supports common wiring schemes used for various automotive relays, including protection for high-current lines and efficient switching for AC components such as fans and compressors. The smaller heat profile assists in applications with tight engine bays or mounting constraints.
KVAEY 2 PCS Car AC Relay
The KVAEY relays emphasize a sealed housing and copper coil with silver alloy contacts for stable electrical connections. This improves resistance to environmental factors such as dust and moisture, while the 25A maximum current rating supports typical automotive AC control circuits, including compressor and fan operations. The design prioritizes durability and reliable performance in damp or demanding driving conditions.
Buying Guide
- Coil voltage and compatibility: Most automotive relays for AC compressors use 12VDC coils. Verify that the coil voltage matches your vehicle’s control circuit and that the relay is compatible with your specific OEM numbers or vehicle model.
- Current rating: Choose a relay with a current rating that exceeds the maximum draw of the compressor circuit and any auxiliary components it controls. Higher current ratings provide margin for startup surges and environmental conditions.
- Sealed housing vs. open design: Sealed housings protect against dust, moisture, and vibration—useful in exposed engine bays. Open or PCB-mount relays may be preferable for compact installations or custom wiring, where heat dissipation is a concern.
- Physical size and mounting: Check the relay’s dimensions and mounting options to ensure it fits within the available space. Low-profile relays reduce clearance issues in tight engine compartments.
- Durability and temperature tolerance: Automotive relays should withstand high temperatures and vibrations. Look for materials described as corrosion-resistant and with robust contact surfaces to minimize wear over time.
- OEM compatibility: If maintaining factory performance is important, opt for GM OE parts or relays advertised as compatible with common OEM numbers (e.g., 39794-SDA-A03, G8HL-H71).
- Wiring configuration: Most relays use a 4-pin configuration (two coil terminals, two contact terminals). Confirm wiring diagrams and pinout to ensure correct integration with existing circuits.
- Installation considerations: When adding relays to control a compressor, ensure proper incorporation of diodes or protective devices if needed, and verify that the control signal isappropriately isolated to avoid interference with other vehicle systems.
- Warranty and sourcing: Choose relays from reputable brands with clear part numbers and documented compatibility to simplify replacement and future maintenance.