Standard Ignition AX221 HVAC Heater Core Temperature Sensor

HVAC Heater Core Temperature Sensor Overview

Standard Ignition AX221 is a direct-fit HVAC heater core temperature sensor built for straightforward replacement on select Ford, Lincoln, and Mercury vehicles. It uses a female plug-in connector with 2 male blade terminals to match the original electrical connection and help restore accurate temperature sensing in the heater core circuit.

Key Features

• Direct-fit OE replacement for the heater core temperature sensor
• Female connector with plug-in design
• 2 male blade terminals for the specified application
• Built with materials intended to handle demanding underhood conditions
• Individually tested for reliability during manufacturing
• Standard Ignition AX221 for HVAC sensor replacement needs

Detailed Product Description

Standard Ignition AX221 is an HVAC heater core temperature sensor designed for vehicles that require a white, 2-blade terminal style sensor in the heater core temperature circuit. It is a direct replacement part for service work on applications such as the Ford Escape, Mercury Mariner, Ford Taurus, Ford Expedition, Lincoln Navigator, and related models. The OE-style fit helps simplify installation while maintaining the original connector and terminal layout. Standard Ignition AX221 is manufactured under controlled quality processes to support consistent performance across the listed applications.

This part cross-references Dayco 70020 for the same application.

Vehicle Fitment

• Fits 2007-2014 Lincoln Navigator, N/A
• Fits 2005-2012 Ford Escape, N/A; White; 2 Blade Term.
• Fits 2005-2011 Mercury Mariner, N/A; White; 2 Blade Term.
• Fits 2007-2009 Ford Expedition, N/A
• Fits 2002-2009 Ford Taurus, N/A
• Fits 2008-2009 Ford Taurus X, N/A
• Fits 2008-2009 Mercury Sable, N/A
• Fits 2002-2005 Mercury Sable, N/A
• Fits 2005-2007 Ford Five Hundred, N/A
• Fits 2005-2007 Mercury Montego, N/A
• Fits 2005-2006 Ford Escape, N/A
• Fits 2006 Mercury Mariner, N/A
• Fits 2002-2005 Ford Thunderbird, N/A

Common Issues This Sensor May Address

• Incorrect heater core temperature readings
• HVAC temperature control concerns tied to sensor failure
• Intermittent sensor signal from worn terminals or connector damage
• Replacement needs after corrosion or heat-related electrical wear
• Service repair for a failed original heater core temperature sensor

Installation Notes and Tips

Verify the connector style, terminal count, and vehicle application before installation. This sensor uses a female plug-in connector with 2 male blade terminals, so matching the original harness connection is important for proper fitment. Confirm the vehicle year and model against the listed applications for Ford Escape, Mercury Mariner, Ford Taurus, and other supported vehicles before replacing the part.

Quality Assurance

Standard Ignition manufactures this sensor with quality control maintained throughout the production process. The part is built from high-quality materials and undergoes extensive testing to support dependable operation in automotive HVAC service.