How to Know If Yours Is Automatic
Look for a tab or lever at the bottom of the mirror. If you don’t see one, the mirror uses automatic dimming because manual mirrors always have that mechanical switch.
Automatic mirrors have a small LED on the face that glows green or amber. The indicator shows the system has power, and it usually sits near the bottom edge of the glass. Some mirrors display AUTO when the feature runs.
Test the system by shining a flashlight at the mirror from behind your seat. The glass should darken gradually within a few seconds. If nothing happens, check the owner’s manual because some systems include an off switch or require activation through vehicle settings.
Most automatic systems let you adjust how aggressively they dim. Some vehicles bury this setting in the dashboard screen, while others put a button directly on the mirror. Adjusting the sensitivity ranks among the most useful night driving tips because factory settings don’t match every driver’s preference.
Older automatic mirrors sometimes fail when the gel degrades or sensors die. The mirror might stay dark permanently, ignore bright lights entirely, or dim inconsistently. Replacement costs depend on what else the mirror includes, so a basic auto-dimming mirror costs less than one with a compass display or garage door opener built in.