my GMC Sierra T1XX (2019-Present) dashboard lights are flickering, what's going on?

Learn how to diagnose and fix flickering dashboard lights in GMC Sierra T1XX (2019-present). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, wrench set, flashlight.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Clean Battery Terminals

• Sub-steps:
  1. Remove the battery terminals using a wrench.
  2. Clean the terminals and battery posts with a wire brush.
  3. Reconnect the terminals, starting with the positive terminal first, then the negative.

3. Replace Faulty Battery

• Sub-steps:
  1. If the battery voltage is below 12.4 volts, consider replacing the battery.
  2. Disconnect the negative terminal, then the positive terminal.
  3. Remove the battery hold-down bracket and lift the battery out.
  4. Install the new battery and secure it with the hold-down bracket.
  5. Reconnect the positive terminal first, then the negative terminal.

4. Repair or Replace Alternator

• Sub-steps:
  1. If the alternator output is not within specified voltage, remove the serpentine belt.
  2. Disconnect the electrical connectors from the alternator.
  3. Remove the mounting bolts and take out the alternator.
  4. Install the new or repaired alternator and secure it with mounting bolts.
  5. Reconnect the electrical connectors and reinstall the serpentine belt.

5. Inspect Wiring and Fuses

• Sub-steps:
  1. Visually inspect wiring harnesses for frays or damage.
  2. Use a multimeter to test continuity of any suspect wires.
  3. Replace any blown fuses related to the dashboard lighting system.