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GMC Sierra T1XX (2019-Present) AC not blowing cold air, what’s the issue? - GMC Sierra
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GMC Sierra T1XX (2019-Present) AC not blowing cold air, what’s the issue?

GMC Sierra T1XX (2019-Present)

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

Problem Statement

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.

Affected Component
HVAC
Estimated Time
2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

  • •Disconnect the battery before working on electrical components.
  • •Allow the engine to cool before performing any repairs to avoid burns.

Symptoms

  • •AC compressor not engaging
  • •Warm air blowing from vents
  • •Unusual noises from the AC system (e.g., hissing or grinding)
  • •AC system pressure readings outside normal range
  • •Ice accumulation on refrigerant lines

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

  • •Multimeter
  • •OBD-II scanner
  • •Refrigerant gauge set
  • •Socket set
  • •Vacuum pump

Parts Required

  • •AC fuse (if blown)
  • •AC compressor (if faulty)
  • •Refrigerant (R-134a or R-1234yf as specified)

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.
  • Disconnect the vehicle battery to ensure safety.
  • Ensure the vehicle is parked on a level surface and the engine is cool.
2. Inspect and Replace AC Fuse
  • Locate the fuse box (refer to the owner's manual for specific location).
  • Remove the AC fuse and inspect it for any signs of damage.
  • Replace with a new fuse of the same amperage if necessary.
3. Repair or Replace AC Compressor
  • If the compressor clutch is not engaging:
    • Remove any belts or components obstructing access to the AC compressor.
    • Disconnect the electrical connector from the compressor.
    • Use a socket set to remove the compressor mounting bolts.
    • Replace the AC compressor with a new unit, ensuring the correct orientation.
    • Reconnect the electrical connector and any belts removed.
4. Recharge AC System
  • Connect the refrigerant gauge set to the low and high-pressure service ports.
  • Evacuate the system using a vacuum pump for at least 30 minutes to remove moisture.
  • Recharge the system with the appropriate type and amount of refrigerant as specified in the owner’s manual (usually R-134a or R-1234yf).
  • Monitor the pressure readings to ensure they are within the manufacturer's specifications.
5. Final Assembly and Testing
  • Reattach any components removed for access.
  • Reconnect the vehicle battery.
  • Start the engine and turn on the AC to test functionality.
  • Check for cold air from the vents and monitor for any unusual sounds.