Fog/Driving Lamp Indicator: Description and Operation

FOG LAMP INDICATOR
A fog lamp indicator is standard equipment on all instrument clusters, but is only functional on vehicles equipped with the optional front and/or rear fog lamps. The fog lamp indicator is located near the upper edge of the instrument cluster overlay, in the upper left quadrant of the cluster. The fog lamp indicator consists of a stencil-like cutout of the International Control and Display Symbol icon for "Fog Lamps" in the opaque layer of the instrument cluster overlay The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. A green lens behind the cutout in the opaque layer of the overlay causes the indicator to appear in green through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The fog lamp indicator is serviced as a unit with the instrument cluster.

The fog lamp indicator gives an indication to the vehicle operator when the optional front and/or rear fog lamps are turned ON. 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 from the fog lamp switch circuitry of the left multi-function switch to the cluster. 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 anytime the front or rear fog lamps are turned on, 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. (Refer to LAMPS/LIGHTING - EXTERIOR/ LEFT MULTI-FUNCTION SWITCH - OPERATION) for more information on the fog lamp switch.