why does my Toyota Highlander Fourth Generation (2020-present) AC blow warm air?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Allow the engine to cool before performing any work.

2. Recharge the AC System

• Tools Required: Manifold gauge set, refrigerant (R-134a), safety goggles, gloves.
• Connect the low-pressure side of the manifold gauge to the AC system service port.
• Start the engine and turn on the AC to the maximum setting.
• Check the pressure readings; if low, proceed to recharge the system.
• Add refrigerant slowly while monitoring the pressure gauge. Fill until it reaches manufacturer specifications.

3. Replace AC Compressor (if faulty)

• Tools Required: Socket set, wrench set, AC compressor removal tool, refrigerant recovery machine.
• Recover refrigerant from the AC system using a recovery machine.
• Remove the serpentine belt by relieving tension with a belt tensioner tool.
• Disconnect electrical connectors and lines from the AC compressor.
• Remove the mounting bolts and carefully take out the compressor.
• Install the new compressor by reversing the removal steps, ensuring all connections are secure.

4. Inspect and Replace AC Condenser (if blocked)

• Tools Required: Socket set, pliers, safety goggles.
• Remove the front grille and any protective covers to access the condenser.
• Check for debris or damage; clean or replace the condenser as necessary.
• Ensure all mounting brackets are secure upon reinstallation.

5. Final Assembly and Testing

• Reconnect the battery.
• Start the vehicle and turn on the AC to check for cold air output.
• Monitor the system for any abnormal noises or leaks.