Pinpoint Test B: All Dimmable Illumination Does Not Dim

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test B: All Dimmable Illumination Does Not Dim

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

Normal Operation

When the side, main or parking lamps are on, the instrument panel dimmer switch (part of the headlamp switch) sends a Pulse Width Modulated (PWM) voltage to the dimmable illumination sources.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Instrument panel dimmer switch (part of the headlamp switch)



PINPOINT TEST B: ALL DIMMABLE ILLUMINATION DOES NOT DIM

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

-------------------------------------------------
B1 CHECK THE EXTERIOR LIGHTING


- Ignition OFF.
- Observe the exterior lighting components.
- Are any exterior lighting components illuminated?

Yes
REFER to Lighting and Horns.

No
GO to B2.

-------------------------------------------------
B2 CHECK THE HEADLAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Disconnect: Headlamp Switch C205.
- Ignition ON.
- Do the dimmable backlighted components continue to illuminate?

Yes
REPAIR the dimmable lighting output circuit for a short to voltage. TEST the system for normal operation.

No
INSTALL a new headlamp switch. TEST the system for normal operation.

-------------------------------------------------