Pinpoint Tests

Clock

Pinpoint Tests

Pinpoint Tests A: The Clock Operation Is Erratic/Inoperative

Refer to Wiring Diagram Set 44, Horn/Cigar Lighter for schematic and connector information. Diagrams By Number

Normal Operation

The clock receives battery voltage from the Central Junction Box (CJB) through circuit 905 (GY/LB). Ground for the clock is supplied through circuit 57 (BK).

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- Clock



PINPOINT TEST A: THE CLOCK OPERATION IS ERRATIC/INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

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A1 CHECK CIRCUIT 905 (GY/LB) FOR AN OPEN


- Ignition OFF.
- Disconnect: Clock C2016.
- Measure the voltage between the clock C2016-6, circuit 905 (GY/LB), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to A2.

No
VERIFY the CJB fuse 21 (10A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.

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A2 CHECK CIRCUIT 57 (BK) FOR AN OPEN


- Disconnect: Negative Battery Cable.
- Measure the resistance between the clock C2016-5, circuit 57 (BK), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
INSTALL a new clock. REFER to Clock Service and Repair. TEST the system for normal operation.

No
REPAIR the circuit. TEST the system for normal operation.

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