Pinpoint Test F: One Or More Dimmable Illumination Source(s) Is Inoperative

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test F: One Or More Dimmable Illumination Source(s) Is Inoperative

Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number

Normal Operation

The instrument panel dimmer switch provides variable voltage to individual illumination sources.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp switch
- 4WD mode switch

PINPOINT TEST F: ONE OR MORE DIMMABLE ILLUMINATION SOURCE(S) IS 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, Mounting and Cables Battery Disconnect.

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F1 CHECK THE INOPERATIVE ILLUMINATION SOURCE

- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Observe the illumination.
- Are all of the illumination sources inoperative?

Yes
GO to Pinpoint Test A. Pinpoint Test A: All Dimmable Switch Illumination Is Inoperative

No
If the headlamp switch illumination is inoperative, GO to F2.

If the 4WD mode switch illumination is inoperative, GO to F4.

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F2 CHECK THE HEADLAMP SWITCH INPUT CIRCUIT FOR AN OPEN

- Disconnect: Headlamp Switch C205.
- Connect a fused jumper wire between the headlamp switch C205-5, circuit CLS30 (VT/WH), harness side and the headlamp switch C205-10, circuit CBP23 (WH/RD), harness side.




- Measure the voltage between the headlamp switch C205-8, circuit VLN18 (BU/WH), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
REMOVE the jumper wire. GO to F3.

No
REMOVE the jumper wire. REPAIR circuit VLN18 (BU/WH) for an open. TEST the system for normal operation.

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F3 CHECK THE HEADLAMP SWITCH GROUND CIRCUIT FOR AN OPEN

- Disconnect: Negative Battery Cable.
- Measure the resistance between the headlamp switch C205-3, circuit GD161 (BK/YE), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
INSTALL a new headlamp switch. REFER to Exterior Lighting Service and Repair. TEST the system for normal operation.

No
REPAIR circuit GD161 (BK/YE) for an open. TEST the system for normal operation.

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F4 CHECK THE 4WD MODE INPUT CIRCUIT FOR AN OPEN

- Disconnect: 4WD Mode Switch C284.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the 4WD mode switch C284-1, circuit VLN18 (BU/WH), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to F5.

No
REPAIR circuit VLN18 (BU/WH) for an open. TEST the system for normal operation.

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F5 CHECK THE 4WD MODE GROUND CIRCUIT FOR AN OPEN

- Place the headlamp switch in the OFF position.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the 4WD mode switch C284-4, circuit GD161 (BK/YE), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
INSTALL a new 4WD mode select switch. REFER to Four Wheel Drive (4WD) Systems . TEST the system for normal operation.

No
REPAIR circuit GD161 (BK/YE) for an open. TEST the system for normal operation.

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