High Beam Indicator: Operation

The high beam indicator gives an indication to the vehicle operator whenever the headlamp high beams are illuminated, or when the exterior lamps are inadvertently left On. This indicator is controlled by a hard wired input to the cluster from the headlamp beam select switch circuitry of the left multi-function switch, and by the instrument cluster circuit board based upon cluster programming based upon hard wired inputs from the head/park/fog lamp switch circuitry of the left multi-function switch, from the driver door ajar switch, and from the ignition switch. The high beam indicator bulb is completely controlled by the instrument cluster logic circuit, and that logic will allow this indicator to operate whenever the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the bulb can be illuminated regardless of the ignition switch position. The bulb only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn on the high beam indicator for the following reasons:

• Beam Select Switch Input  - Each time the cluster detects battery current on the beam select switch sense circuit (beam select switch closed = high beams selected or optical horn feature activated) the high beam indicator will be illuminated solid. This input can occur when the headlamp high beams are selected or when the optical horn feature is activated. The indicator remains illuminated until the beam select switch sense input to the cluster is an open circuit (beam select switch open = high beams not selected and optical horn feature not activated), or until the exterior lighting is turned off, whichever occurs first.
• Exterior Lamps-On Optical Warning  - Each time the cluster detects battery current on the headlamp switch output circuit (park or head lamp switch closed = exterior lighting is On), ground on the driver door ajar switch sense circuit (driver door ajar switch closed = driver door is open), and the fused ignition switch output (run-start) input is an open circuit (ignition switch is in a position other than On or Start), the high beam indicator will be flashed on and off repeatedly. The indicator will continue to flash until the exterior lighting is turned Off, until the driver door is closed, or until the ignition switch is turned to the On or Start positions, whichever occurs first.
• Actuator Test  - Each time the cluster is put through the actuator test, the high beam indicator will be turned on, then off again during the bulb check portion of the test to confirm the functionality of the bulb and the cluster control circuitry.

The instrument cluster continually monitors the headlamp beam select switch and circuitry integral to the left multi-function switch, the driver door ajar switch, and the ignition switch and turns the high beam indicator on or off accordingly. For further diagnosis of the high beam indicator or the instrument cluster circuitry that controls the indicator, (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING  ). The left multi-function switch, driver door ajar switch, and ignition switch inputs to the instrument cluster can be diagnosed using conventional diagnostic tools and methods.