At a Glance

• Condition: OEM used analog anti-theft immobilizer unit, electrical function tested, connector or pigtail harness integrity verified, mounting features inspected
• Availability: In stock for classic Mercury Grand Marquis and Marquis family applications
• Shipping: Free shipping to all 50 states, 3 to 7 business days
• Application: Mercury Grand Marquis and Marquis family, 1979 and earlier US market - classic Mercury full-size sedan analog ignition applications
• Analog anti-theft interrupt: Vintage-era analog electrical circuit anti-theft interrupt system - fundamentally different from modern electronic PATS (Passive Anti-Theft System) transponder-key systems
• NOT compatible with post-1980 vehicles: Different ignition system architecture post-1980 makes this unit incompatible with 1980+ Grand Marquis / Marquis applications per the source data
• Vintage-style connector: Includes vintage-style connector or pigtail harness appropriate for classic Mercury analog electrical systems
• Panther platform predecessor context: The classic Mercury Grand Marquis was part of Mercury's full-size sedan lineage that later evolved into the famous Panther platform Grand Marquis (1979+, closely related to the Ford Crown Victoria)
• Related classic Mercury: See our related Mercury Monarch gas tank listing for classic Mercury heritage context
• Other vintage analog-ignition vehicle compatibility possible: Call to confirm circuit match for other classic vehicles
• 15 day replacement warranty on component defects, classic-vehicle disclosure applies