Blower Motor Resistor & Thermal Limiter
WARNING: This page is about a different car, the 2002 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
Blower motor resistor assembly (located on evaporator core housing behind glove box) allows 4-speed operation and contains a thermal limiter, which serves as a temperature protection fuse. Thermal limiter is located at a preset distance from resistor coils. If temperature of thermal limiter reaches about 250°F (121°C), limiter contacts will open. This interrupts all blower speed operations. If thermal limiter opens, resistor assembly must be replaced.