Circuit/System Verification
WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition/vehicle off
- Test for 12.4 - 12.8 V between the battery posts.
- If not between 12.4 - 12.8 V
Refer to: Battery Inspection/Test
- Go to next step: If between 12.4 - 12.8 V
- If not between 12.4 - 12.8 V
- Start the engine and allow it to idle for 15 s.
- Turn all electrical accessories off.
- Test for 13.4 - 15 V between the battery posts.
- If not between 13.4 - 15 V
Refer to: Charging System Test
- Go to next step: If between 13.4 - 15 V
- If not between 13.4 - 15 V
- Refer to Circuit/System Testing
NOTE:
The battery voltage should stabilize after a few minutes of turning the ignition/vehicle Off.