How to Troubleshoot the Air Conditioning in Toyota Cars

by Contributing Writer; Updated June 12, 2017

If you reach for the A/C in your Toyota car in the middle of summer and all you receive is a blast of hot air, your A/C system may be experiencing a number of issues. However, you can diagnose many problems on your own, such as insufficient pressure in the A/C system or a refrigerant leak. Before taking your Toyota car to the shop for what could be an expensive visit, you can run through a few troubleshooting steps.

Under The Hood:

 How to Troubleshoot the Air Conditioning in a Toyota Camry

Start the engine and let it to run for a few minutes to allow the air to cool. Double check the controls to make sure the correct buttons are selected. This may seem simplistic, but human error could be to blame.

Adjust the climate controls. If they seem to work fine but have effect on the air then the problem is probably a simple blown fuse. If the controls do not work correctly, then the problem is probably with the control panel. If you cannot hear the sound that accompanies turning the air from low to high, then the problem is likely with the blower motor.

Check for a blown fuse. The interior fuse box is located to the left of the steering column in the dashboard. Remove the coin tray, and then remove the trim panel surrounding it. Use the guide on the inside of the fuse panel to locate the blown fuse and replace it with one of equal amperage.

Get to the blower motor pretty easily in a Toyota Camry. Unscrew and remove the glove box entirely. The blower motor is directly behind it. Unplug the electrical connection, unscrew it and remove it.

Pry off the trim panels surrounding the climate controls and radio to gain access to the control panel. Press the two fitting tabs in toward one another to release the heater control assembly.

Items you will need

  • Screwdriver

 How to Troubleshoot the Air Conditioning on a Toyota Tercel

Start the vehicle and turn the A/C control up to the coldest setting. Open the hood and place your hand above the hoses near the firewall. Both of the hoses should be warm to the touch but one should be noticeably cooler. If they are both the same temperature, the problem could lie with the valve control. Have a mechanic check this out for you because the valve control may need to be replaced.

Set the A/C to its highest setting (with the engine running) and open the hood. Watch for the magnetic clutch that is connected to the A/C compressor to kick on. If you do not see the clutch begin to turn, the wiring could be bad, or a fuse may have blown. Have a mechanic check to see if the compressor has seized.

Check the A/C dials and switches on the dashboard for any looseness or resistance. Replace the switches if they are damaged. Ensure that the electric fan is turned on as well as the A/C. If you cannot hear the fan kick on, a fuse may have blown, or the fan may need to be replaced.

Ensure that there is sufficient coolant in the radiator and refill, if needed. Check all the A/C hoses for any damage or kinks. If a hose is kinked, grip the hose between your thumb and forefinger and squeeze the hose until the kink has diminished. Replace any hoses that are damaged or leaking.

Check for sufficient pressure in the A/C system. Attach the A/C pressure gauge test. Attach the blue-coded hose to the low-side port, and the red-coded hose to the high-side port. A normal reading is between 50 psi (pounds per square inch) and 80 psi. Have a mechanic check the system for any leaks if the readings are lower than this.

Items you will need

  • Air conditioner pressure gauge

 How to Troubleshoot the Air Conditioning in a Toyota Tundra

See if the problem is as simple as a blown fuse. If the temperature controls on the dashboard seem to work fine but have no effect on the air temperature, then this is probably the cause. The fuse box in a Tundra is located below and to the left of the steering wheel by the brake.

Listen for the blower motor sound to increase when turned to high and decrease when turned low. Get to the blower motor in your Tundra by unscrewing the glove box and pulling it out. Unplug the electrical connectors and unscrew the motor and fan.

Check the coolant levels. The coolant reservoir is found under the hood at the very front of the vehicle. It is white and plastic. Open the cap and shine a flashlight into the reservoir. Make sure the coolant level is less than the full line but more than the low line.

Adjust the climate controls. If they do not feel right with the correct amount of resistance and pausing in the right locations then the problem is probably the control panel. Getting to the control panel in a Tundra is very difficult, and will probably need to be done by a mechanic.

Items you will need

  • Flashlight

 How to Troubleshoot the Air Conditioning in a Toyota Tacoma

Start the engine and let it to run for a few minutes to allow the air to cool. Double check the controls to make sure the correct buttons are selected.

Check the coolant levels if the air seems to run fine but does not get cool. The coolant reservoir is under the hood at the very front of the vehicle in a white plastic container with a cap. Lift the cap, shine a flashlight into the reservoir and look at the side to make sure the level is more than the low line but less than the full line.

Adjust the climate controls on the dashboard. If they seem to work normally but do not increase the air flow, then it is probably a blown fuse. Find the interior fuse on the left side of the dash to the left of the steering column.

Listen for the normal blowing noise when the air is running to increase when air is turned to high and decrease when air is turned back low. This indicates the blower motor and fan are working correctly.

Get help with the control panel if the climate controls do not work at all. Getting to the control panel of a Tacoma is very complicated and needs to be done by a professional.

Items you will need

  • Flashlight

 How to Troubleshoot the Air Conditioning in a Toyota Corolla

Check the coolant levels in the coolant reservoir. Lift the hood of the vehicle. Find the reservoir in the very front of the vehicle on the driver's side. It is a plastic white jug.

Lift the lid and shine a flashlight into it. Look at the side of the jug to make sure the level of the coolant is in between the low line and the full line.

See if the problem is a simple blown fuse next. If the temperature controls on the dashboard seem to work correctly but have no effect whatsoever on the air, this is likely the problem. The fuse box in a Toyota Corolla is located to the left of the steering wheel behind the coin tray. Pull up and out on the coin tray to remove it.

Make sure the control panel is working properly. If the climate controls do not work at all, then there is a problem with the control panel. Find the control panel by prying off the top instrument panel around the air conditioning temperature controls. Press the two fitting tabs in toward one another to release the heater control assembly.

Find the blower motor easily in a Toyota Corolla. If the air doesn't increase and decrease with the fan controls, than there is a problem with the blower. Unscrew and remove the glove box assembly. The blower motor is directly behind the glove box. Unplug the electrical connection, unscrew it and remove it.

Items you will need

  • Screwdriver

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.