Dashboard Warning Light Misidentified as Headlight Indicator - Tail Light Failure Sensor

During interior reassembly of an 89 Turbo Supra, the dashboard warning light that the owner believed was a headlight indicator was not illuminating when headlights were switched on, despite both headlight bulbs working on low and high beam. Additionally, the door open warning light on the dash was not coming on even though dome and door lights functioned normally.

The dashboard warning light was misidentified by the owner. The light in question is not a headlight indicator — it is the tail light failure warning sensor. The tail lights/brake running lights were not working properly (likely not reconnected during reassembly), which is what the warning system monitors. The door open warning light issue was likely a burnt out bulb in the gauge cluster.

Moderate confidence — Original poster confirmed this resolved the issue