Schematic Reference: Interior Lights Dimming 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 maximum to minimum.

Does the interior backlighting operate properly?

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

Go to Step 3

1. Disconnect the I/P dimming module.
2. Connect a test lamp from the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch to battery positive voltage.
3. Slowly rotate the I/P dimmer switch from maximum to minimum while observing the test lamp.

Does the test lamp dim with the I/P dimmer switch rotation?

Go to Step 4

Go to Step 7

1. Connect a 3-amp fused jumper between battery positive voltage and the instrument panel lamp supply voltage circuit.
2. Disconnect and reconnect the fused jumper.

Do all of the backlighting lamps turn On and OFF?

Go to Step 8

Go to Step 5

1. Turn OFF the ignition.
2. Reconnect the I/P dimming module.
3. Disconnect the component with non-dimming backlighting lamps.
4. Connect a test lamp between the backlight lamps instrument panel lamp supply voltage and the backlight lamps ground circuit of the component with non-dimming backlighting lamps.
5. Turn ON the ignition, with the engine OFF.
6. Slowly rotate the dimming switch from maximum to minimum while observing the test lamp.

Does the test lamp dim with the dimming switch rotation?

Go to Step 10

Go to Step 6

Test the non-dimming backlight lamps instrument panel lamp supply voltage for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

Test the I/P dimmer switch ground circuit for an open high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 9

Test the ground circuit of the IP dimming module for an open high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

Test the instrument panel lamps dimmer switch signal circuit of the I/P dimmer switch for an open, a short to ground or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

Inspect for poor connections at the harness connector of the component with the non-dimming 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 16

Go to Step 13

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 16

Go to Step 14

Inspect for poor connections at the harness connector of the dimming 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 16

Go to Step 15

Replace the component with the non-dimming backlighting lamps.

Did you complete the replacement?

Go to Step 16

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

Did you complete the replacement?

Go to Step 16

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

Did you complete the replacement?

Go to Step 16

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2