GMC Sierra T1XX (2019-Present) AC not blowing cold air

Learn how to diagnose and fix AC not blowing cold air in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools: OBD-II scanner, manifold gauge set, multimeter, socket set, and safety goggles.
• Disconnect the battery to ensure safety while working on electrical components.

2. Recharge Refrigerant

• Sub-steps:
  1. Connect the manifold gauge set to the low and high-pressure ports on the AC system.
  2. Check the pressure readings; if low, proceed to recharge the system.
  3. Use the correct refrigerant (R-134a or R-1234yf, based on the model) and follow the manufacturer's specifications for amount.
  4. Start the vehicle and run the AC on maximum to allow the new refrigerant to circulate.

3. Repair or Replace AC Compressor

• Sub-steps:
  1. Remove any obstructions to access the AC compressor.
  2. Disconnect the electrical connector from the AC compressor and remove the mounting bolts using a socket set.
  3. Remove the old compressor and replace it with a new unit, ensuring the alignment is correct.
  4. Reconnect the electrical connector and torque the mounting bolts to manufacturer specifications.

4. Replace Cabin Air Filter

• Sub-steps:
  1. Locate the cabin air filter compartment, usually behind the glove box.
  2. Remove the cover and take out the old air filter.
  3. Install a new cabin air filter, ensuring it is oriented correctly.
  4. Reattach the cover securely.

5. Check and Clean AC Condenser

• Sub-steps:
  1. Inspect the AC condenser for debris, dirt, or blockage.
  2. Clean the condenser using compressed air or a gentle rinse with water.
  3. Ensure there is adequate airflow around the condenser.