my Toyota Highlander Fourth Generation (2020-present) AC compressor is not engaging what do I check

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on electrical components.

2. Check and Recharge Refrigerant

• Tools Required: Refrigerant gauge set, refrigerant canister
  • Connect the low-pressure side of the refrigerant gauge to the AC service port.
  • Check the pressure readings. If low, proceed to recharge the system with the appropriate refrigerant (R-1234yf for 2020-present Highlander).
  • After recharging, monitor the system for proper operation.

3. Inspect and Replace AC Compressor Clutch

• Tools Required: Socket set, torque wrench
  • Remove the serpentine belt by using a wrench to relieve tension on the tensioner pulley.
  • Unbolt the AC compressor from its mounting bracket.
  • Remove the compressor clutch by unscrewing the retaining screws and pulling the clutch off the compressor.
  • Replace the clutch if worn and reinstall it, ensuring it is properly aligned.

4. Check and Replace AC Relay

• Tools Required: Multimeter, socket set
  • Locate the AC relay in the fuse box.
  • Remove the relay and test it for continuity using a multimeter.
  • Replace with a new relay if it fails the continuity test.

5. Reconnect Battery and Test AC System

• Reconnect the battery terminals.
• Start the vehicle and activate the AC system to check if the compressor engages and cool air is produced.