Schematic Reference: Interior Lights Dimming Schematics or Interior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Turn ON the ignition, with the engine OFF.
2. Turn ON the park lamps.
3. Operate the I/P dimmer switch from minimum to maximum position.

Does the interior backlighting operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Do the park lamps operate properly?

Go to Step 4

Go to Park Lamps Inoperative

Is the component with the inoperative backlighting a rear window switch?

Go to Step 5

Go to Step 6

1. Disconnect the rear window switch.
2. Turn ON the park lamps.
3. Connect a test lamp between the backlight lamps park lamp supply voltage circuit of the rear window switch and the backlight lamps ground circuit of the rear window switch.

Does the test lamp illuminate?

Go to Step 15

Go to Step 10

1. Turn OFF the ignition.
2. Disconnect the I/P dimming module.
3. Connect a 3-amp fused jumper between battery voltage and the instrument panel lamp supply voltage circuit.

Are all of the interior backlighting lamps inoperative?

Go to Step 8

Go to Step 7

1. Disconnect the component with the inoperative backlighting lamps.
2. Connect a test lamp between the backlight lamps instrument panel lamp supply voltage circuit of the component and the backlight lamps ground circuit of the component.

Does the test lamp illuminate?

Go to Step 15

Go to Step 11

1. Turn ON the park lamps.
2. Connect a test lamp between the IP dimming modules park lamp supply voltage circuit and the I/P dimming modules ground circuit.

Does the test lamp illuminate?

Go to Step 9

Go to Step 14

1. Position the I/P dimmer switch to maximum brightness.
2. Connect a test lamp between battery voltage and the I/P dimming modules instrument panel lamps dimmer switch signal circuit.

Does the test lamp illuminate?

Go to Step 17

Go to Step 12

Test the park lamp supply voltage circuit of the rear window switch backlight lamps for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Test the backlight lamps instrument panel lamp supply voltage circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Test the I/P dimmer switch ground circuit for a high resistance, a open or a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 13

Test the I/P dimming modules instrument panel lamps dimmer switch signal circuit for a high resistance, an open or a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 16

Test the I/P dimming modules park lamp supply voltage circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 19

Inspect for poor connections at the harness connector of the component with the inoperative backlighting lamps. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 20

Inspect for poor connections at the harness connector of the I/P dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 21

Inspect for poor connections at the harness connector of the I/P dimming module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 22

Repair high resistance or open in the backlight lamps ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 23

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Repair the high resistance or an open in the IP dimming modules ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 23

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1. Replace the inoperative backlighting bulbs in the component if they are replaceable. See the appropriate systems operation and description.
2. If the bulb is not replaceable replace the component with inoperative backlighting lamps.

Did you complete the replacement?

Go to Step 23

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Replace the I/P dimmer switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 23

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Replace the I/P dimming module. Refer to Panel Dimming Module Replacement .

Did you complete the replacement?

Go to Step 23

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2