There are 1 owner-reported lighting complaints for the 2003 Mercury Mountaineerin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
INTERMITTENTLY THE BRAKE LIGHTS STAYING LIT AFTER VEHICLE IS TURNED OFF AND KEY IS REMOVED. LIKELY THAT THIS FAILURE ALSO CAUSED THE BRAKE LIGHTS TO REMAIN LIT WHILE DRIVING, RENDERING THE SIGNAL INEFFECTIVE. LIGHTS ACTUALLY STAYED ON TWO OCCASIONS CAUSING A DEAD BATTERY ONCE. LIGHTS WERE NOTICED THE SECOND TIME, AND WIGGLING THE BRAKE PEDAL EXTINGUISHED ALL THREE INDICATORS. DEALER REPLACED THE BRAKE LIGHT SWITCH UNDER WARRANTY. *NLM
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026