Lamp Out Indicator: Description and Operation

If a rear lamp fails the Integrated Central Electronics (ICE) unit sends a message to the Saab Information Display (SID) unit which grounds the "FAULTY BULB" indicator lamp in the main instrument display panel via pin 3 (12p-1).

If a bulb at the front is faulty, the filament monitor grounds the indicator lamp in the main instrument display panel via the SID unit.

The lamp is supplied with current in the main instrument display panel.