Universal Air SW9978C HVAC Blower Motor Resistor - Rear

HVAC Blower Motor Resistor for Ford and Lincoln

Universal Air SW9978C is an HVAC blower motor resistor for vehicles with manual blower speed control. It restores proper fan-speed operation when the blower only works on certain settings or stops responding altogether. This blower resistor is listed for select Ford Escape, Ford Mustang, Ford F-150, Ford Expedition, Ford Excursion, Mercury Mariner, and Lincoln Navigator applications.

Key Features

• HVAC blower motor resistor for manual fan-speed control systems
• Direct fit for select Ford, Mercury, and Lincoln applications
• Fits 2001-2007 Ford Escape, with Floor Console
• Fits 2005-2007 Mercury Mariner
• Fits 2003-2006 Ford Expedition, rear
• Fits 2003-2006 Lincoln Navigator, rear
• Fits 2000-2005 Ford Excursion, rear
• Fits 1994-2004 Ford Mustang
• Fits 1997-2002 Ford Expedition and 1998-2002 Lincoln Navigator without Automatic Temperature Control
• Part number SW9978C for application matching and catalog lookup

Detailed Description

Universal Air SW9978C is a blower resistor used in HVAC systems to regulate blower motor speed through the dash control switch. When the resistor fails, common symptoms include loss of one or more fan speeds, intermittent blower operation, or a blower that only runs on the highest setting. This part number SW9978C covers a broad range of Ford Mustang, Ford F-150, Ford Escape, Ford Expedition, Ford Excursion, Mercury Mariner, and Lincoln Navigator fitments, including rear HVAC applications where listed.

This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

Common Problems It Can Solve

• Blower motor works only on high speed
• One or more HVAC fan speeds do not operate
• Intermittent cabin airflow from the vents
• No blower response from the climate control switch
• Rear HVAC fan-speed failure on listed Expedition, Navigator, and Excursion applications

Installation Notes and Tips

Verify the vehicle uses a manual blower speed control system before ordering. The 2004 Ford F-150 Heritage listing is not compatible with Automatic Temperature Control, and the 1997-2002 Ford Expedition and 1998-2002 Lincoln Navigator listings also exclude Automatic Temperature Control systems. Confirm the connector style, mounting location, and vehicle position before installation. For best results, inspect the blower motor and related wiring for heat damage or corrosion when replacing the resistor.

Quality Assurance

Universal Air SW9978C is cataloged as an HVAC blower motor resistor for the listed Ford, Mercury, and Lincoln applications. Use the fitment details above to confirm the correct application before purchase.