Pinpoint Test I: The Courtesy Lamps Are Inoperative From The Instrument Panel Dimmer Switch

Interior Lighting

Pinpoint Tests

Pinpoint Test I: The Courtesy Lamps Are Inoperative From The Instrument Panel Dimmer Switch

Refer to Wiring Diagram Set 89, Interior Lighting for schematic and connector information. Diagrams By Number

Normal Operation

The Smart Junction Box (SJB) monitors the instrument panel dimmer switch status on circuit CLN28 (GN/BU) to determine if the courtesy lamps are requested. Based on the instrument panel dimmer switch status, the SJB supplies voltage to the courtesy lamps through circuit CLN03 (YE/GY).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Dimmer switch
- SJB



PINPOINT TEST I: THE COURTESY LAMPS ARE INOPERATIVE FROM THE INSTRUMENT PANEL DIMMER SWITCH

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

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I1 CHECK THE INSTRUMENT PANEL DIMMER SWITCH


- Ignition OFF.
- Disconnect: Instrument Panel Dimmer Switch C2065.
- Connect a fused jumper wire between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-4, circuit RLN29 (WH/OG), harness side.




- Do the courtesy lamps illuminate?

Yes
REMOVE the jumper wire. INSTALL a new instrument panel dimmer switch. TEST the system for normal operation.

No
REMOVE the jumper wire. GO to I2.

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I2 CHECK CIRCUIT CLN28 (GN/BU) FOR A SHORT TO VOLTAGE


- Disconnect: SJB C2280b.
- Ignition ON.
- Measure the voltage between the SJB C2280b-51, circuit CLN28 (GN/BU), harness side and ground.




- Is any voltage present?

Yes
REPAIR the circuit. TEST the system for normal operation.

No
GO to I3.

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I3 CHECK CIRCUIT CLN28 (GN/BU) FOR AN OPEN


- Disconnect: SJB C2280b.
- Ignition OFF.
- Measure the resistance between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and the SJB C2280b-51, circuit CLN28 (GN/BU), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to I4.

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

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I4 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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