Fog Lamp Indicator: Operation

The fog lamp indicator gives an indication to the vehicle operator whenever the optional front and/or rear fog lamps are illuminated. The availability of the front fog lamps, or rear fog lamps options varies by the market for which the vehicle is manufactured. This indicator is controlled by a hard wired input to the cluster from the fog lamp switch circuitry of the left multi-function switch. The fog lamp indicator Light Emitting Diode (LED) is grounded on the instrument cluster electronic circuit board at all times. Therefore, the LED will be on any time the front or rear fog lamps are illuminated, regardless of the ignition switch position. The LED only illuminates when it is provided battery current by the fog lamp switch circuitry of the left multi-function switch.

The fog lamp switch circuitry of the left multi-function switch is connected in series between a fused B(+) fuse in the Power Distribution Center (PDC) and the front or rear fog lamp feed input to the instrument cluster through the fog lamp relay, which is also in the PDC. The fog lamp switch input to the instrument cluster can be diagnosed using conventional diagnostic tools and methods. For proper diagnosis of the fog lamp switch and circuits, (Refer to LEFT MULTI-FUNCTION SWITCH - DIAGNOSIS AND TESTING ).