why does my GMC Sierra T1XX (2019-Present) AC stop blowing cold air?

GMC Sierra T1XX (2019-Present)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

569 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 systems.
•Allow the engine to cool before opening any components related to the AC system.

Symptoms

•AC system not cooling air
•Unusual noises from the AC compressor
•AC clutch not engaging
•Warm air blowing from vents
•Reduced airflow from the AC vents
•Check engine light illuminated (if related to AC system)

Diagnostic Steps

1
Check the refrigerant level using a pressure gauge to ensure it's within specifications.
2
Inspect the AC compressor for signs of wear or damage.
3
Scan for error codes using an OBD-II scanner to identify any related issues.
4
Examine the AC fuse and relay for continuity and functionality.
5
Inspect the cabin air filter for clogs that could restrict airflow.
6
Test the AC control module and switches for proper operation.

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
•Refrigerant gauge set
•Refrigerant canister
•Socket set
•Torque wrench
•AC compressor removal tool
•Screwdriver

Parts Required

•Refrigerant (if low)
•AC compressor (if defective)
•Cabin air filter (if clogged)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Check the refrigerant level using a pressure gauge to ensure it's within specifications.
2
Inspect the AC compressor for signs of wear or damage.
3
Scan for error codes using an OBD-II scanner to identify any related issues.
4
Examine the AC fuse and relay for continuity and functionality.
5
Inspect the cabin air filter for clogs that could restrict airflow.
6
Test the AC control module and switches for proper operation.

Solution

1. Preparation

Gather tools and parts required for the repair.
Disconnect the negative battery cable to avoid electrical shorts.
Allow the engine to cool before working on the AC components.

2. Recharge Refrigerant

Tools Required: Refrigerant gauge set, refrigerant canister
Connect the refrigerant gauge set to the service ports on the AC system (high and low).
If refrigerant is low, add refrigerant according to manufacturer specifications, monitoring pressure throughout the process.
Check for leaks in the system using UV dye or electronic leak detector.

3. Replace AC Compressor (if necessary)

Tools Required: Socket set, torque wrench, AC compressor removal tool, refrigerant recovery machine
Remove the serpentine belt by releasing the tension from the belt tensioner.
Disconnect electrical connectors and refrigerant lines from the AC compressor.
Remove mounting bolts and take out the AC compressor.
Install the new AC compressor, ensuring all connections are tight.
Reconnect refrigerant lines and electrical connectors, and tighten mounting bolts to manufacturer's torque specifications.

4. Replace Cabin Air Filter (if clogged)

Tools Required: Screwdriver (if necessary)
Locate the cabin air filter compartment, usually behind the glove box or under the dashboard.
Remove the old cabin air filter and clean the compartment.
Install the new cabin air filter, ensuring it is oriented correctly.

5. Test AC System

Reconnect the negative battery cable.
Start the engine and turn on the AC system to monitor for proper cooling.
Check for any unusual noises or leaks.