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how to fix the rear AC not working on my Toyota Highlander - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/how to fix the rear AC not working on my Toyota Highlander

how to fix the rear AC not working on my Toyota Highlander

Toyota Highlander Fourth Generation (2020-present)

Error Codes
2-4 hours
Time
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
3 min read
547 words

Problem Statement

Learn how to diagnose and fix the rear AC not working in your Toyota Highlander. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

Affected Component
HVAC
Estimated Time
2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

  • •Disconnect the battery before working on electrical components.
  • •Be cautious when handling refrigerant; use gloves and goggles.

Symptoms

  • •Rear AC vents blowing warm air
  • •No airflow from rear AC vents
  • •Unusual noises from the rear AC unit
  • •Front AC functioning normally while rear AC is not
  • •Rear AC control panel unresponsive or malfunctioning

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II scanner
  • •Multimeter
  • •Screwdriver set
  • •Refrigerant gauge
  • •Safety glasses

Parts Required

  • •Rear AC blower motor (if faulty)
  • •Rear AC fuse (if blown)
  • •Refrigerant (if low)

Additional Information

Affected Component
HVAC
Estimated Time
2-4 hours
Difficulty
medium
Severity
medium
Tools Required
5 items
Parts Required
3 items

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Solution
1. Preparation
  • Gather necessary tools and parts.
  • Ensure the vehicle is parked on a level surface and the engine is off.
  • Disconnect the negative battery terminal to prevent electrical shorts.
2. Check and Replace the Fuse
  • Locate the fuse box (usually under the dashboard or in the engine compartment).
  • Identify the fuse related to the rear AC (refer to the owner's manual for the specific location).
  • Remove the fuse and inspect it; replace it with a new one if blown (use the same amperage).
3. Inspect and Replace the Blower Motor
  • Access the rear AC blower motor by removing the rear panel (if applicable).
  • Disconnect the electrical connector from the blower motor.
  • Test the blower motor using a multimeter; if it does not operate, replace it.
  • To install a new blower motor, reverse the removal steps and reconnect the electrical connector.
4. Check and Recharge Refrigerant
  • Connect a refrigerant gauge to the low-pressure service port of the rear AC system.
  • Check the pressure readings; if low, recharge the system with the appropriate refrigerant (usually R-134a).
  • Follow manufacturer specifications for the amount of refrigerant to add.
5. Clear Any Blockages in Ducts
  • Inspect the rear AC ducting for any visible obstructions.
  • Remove any debris or blockages that may restrict airflow.
  • Ensure that the air cabin filter is clean; replace if necessary.