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Home >> Ford Truck >> 2008 >> E 150 V8-5.4L >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Testing and Inspection >> Pinpoint Tests >> Instrument Cluster and Panel Illumination >> Test A: The Control Illumination Is Inoperative/Always On

Test A: The Control Illumination Is Inoperative/Always On

PINPOINT TEST A: THE CONTROL ILLUMINATION IS INOPERATIVE/ALWAYS ON

Normal Operation
Battery voltage is supplied to the headlamp switch through circuit 195 (TN/WH). The instrument panel dimmer switch is an integral part of the headlamp switch. The instrument panel dimmer switch controls and sends a variable voltage supply to the central junction box (CJB) fuse 36 (5A) through circuit 1045 (DB/WH). Circuit 19 (LB/RD) then provides the variable voltage to the various illumination components.

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Instrument panel dimmer switch (part of the headlamp switch)


A1-A5:






A5-A6:




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