GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    •  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Clock Battery Positive Voltage Circuit

1

1

--

--

Clock Ground Circuit

--

1

--

--

1. Clock Malfunction

Circuit/System Description

The instrument panel is equipped with an analog clock. The analog clock utilizes the clock battery positive voltage circuit and the clock ground circuit to operate. An open circuit condition, a high resistance or a short to ground in the battery positive voltage circuit or the ground circuit will cause the clock not to operate properly.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

    •  Displays and Gages Connector End Views
    •  Inline Harness Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the clock.
  2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal 2 and ground.
  3. If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and the ground circuit terminal 2.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the clock.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Clock Replacement