Normal Operation

The headlamp switch supplies the instrument cluster with the headlamp switch position status. For additional information on the headlamp switch operation, Refer to EXTERIOR LIGHTING . The dimmer switch provides the instrument cluster with the dimmer control status through signal circuit 8-LE10 (WH/BK) and return circuit 9-LE10 (BN/YE). The instrument cluster sends the illumination message to the front electronic module (FEM) over the standard corporate protocol (SCP) communication network, circuits 4-EG8 (GY/VT) and 5-EG8 (BU/WH), based upon the dimmer switch position. The FEM is supplied with illumination power through circuit 29S-DK22 whenever the switched system power (SSP) is energized. For additional information on the SSP operation, Refer to EXTERIOR LIGHTING . When the headlamp switch is in the PARK, HEADLAMP, or AUTOLAMP ON position, the instrument cluster sends the FEM an illumination message and the FEM, in turn, provides a pulse width modulation (PWM) power to the interior auxiliary junction box through circuit 64S-LH5 (BU/YE). The interior auxiliary junction box separates the PWM power and supplies it to sub-illumination sources through circuits 64S-LH4 (BU/BK), 64S-LH1 (BU), 64S-LK9 (BU/WH), 64S-LH16 (BU/WH), 64S-LH1 (BU), and the central junction box (CJB) through circuit 64S-AD2 (BU/RD). The CJB separates the PWM power and also supplies it to sub-illumination sources through circuits 64S-LH2 (BU/RD) and 64S-LH33 (BU/BK). The sub-illumination sources then provide the PWM power to the individual illuminating sources.