Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How to Replace an Air Conditioning Compressor Relay

How to Replace an Air Conditioning Compressor Relay

relay in person

Relays are used in many circuits throughout your vehicle. One such circuit is that of the A/C compressor. The compressor has a belt driven clutch which is cycled on and off to keep your A/C blowing cool. Power is supplied to this clutch through a relay.

A relay is a simple device composed of a coil and set of contacts. When current passes through the coil, a magnetic field is formed. This field draws the contacts together and completes the circuit.

The electronic control module monitors the status of sensors in your vehicle to determine if the conditions are correct for A/C operation. If these conditions are met, the module will energize the A/C relay coil when the A/C button is pushed. This allows power to flow through the relay to the compressor clutch, turning your A/C on.

Part 1 of 2: Locate your A/C relay

Material Needed

  • Owner’s manual

layout of the AC system

Step 1: Locate the A/C relay. The A/C relay is typically found in the underhood fuse box.

Consult your owner’s manual for the exact location.

Part 2 of 2: Replace your A/C relay

Materials Needed

  • Pliers
  • Protective gloves
  • Safety glasses

hand removing the relay

Step 1: Remove the relay. Remove the A/C relay by pulling it straight up and out.

If it is difficult to grasp, you can gently use pliers to remove it.

  • Warning: Be sure to wear safety goggles and gloves at all times.

Step 2: Purchase the new relay. Note the year, make, model and engine size of your vehicle and take the relay with you to your local parts store.

Having the old relay and the vehicle information will enable the parts store to supply you with the correct, new relay.

installing the new relay

Step 3: Install the new relay. Install the new relay by aligning its terminals with the slots in the fuse box and carefully push it in.

turning on the AC

Step 4: Test the A/C. Test the A/C to see if it’s working. If it is, then you have successfully replaced the compressor relay.

Th A/C compressor relay is a small part that plays a big role, as with many parts in your car. Luckily, it is an easy fix if one goes bad, and hopefully replacing it will get your car’s system back to working condition. If your A/C is still not working, you should have your A/C system inspected by a trained professional.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...


Related questions

Q: 1994 GMC Sonoma not getting power to fuel pump

The problem is somewhere in the fuel pump relay control circuit. There are five relay terminals: battery power, ignition power (controlled by the ECM), ground, output to the pump and connection to the fuel pump prime connector. What the prime...

Q: Where can i get a good ac compressor for my toyota sienna 2004 but wont break the bank?

Unfortunately, a/c repairs can be hard to save money on due to the special tools required, the need to open the system for many a/c repairs (which requires time consuming recovery, evacuation and re-charging) and the difficulty of using used...

Q: Main relay, EMS1 fuses, and EMS2 fuses are missing. Do I need these parts?

Hi there. The codes are coming up for the camshaft position sensor, Oxygen sensor, EGR valve, and evaporative system not working. The fuses for EMS1 and EMS2 and the main relay vary depending on what Aveo model you have. If...