If you have a manual system, you have a resistor. If electronic, you have a blower motor speed controller. Please rate if this helps.
here is info:
Control System Outputs-Manual A/C
Blower Motor Switch Resistor
The heater blower motor switch resistor has the following features:
Control System Outputs-EATC
Blower Motor Speed Control
- The assembly is located on the evaporator housing in the engine compartment.
- Three resistance elements are mounted on the resistor board to provide four blower motor speeds.
- Depending on the heater blower motor switch position, series resistance is added or bypassed in the blower motor circuit to decrease or increase blower motor speed.
- An overheating protective device (thermal limiter) will open the resistor coil circuit when the temperature reaches 121°C (250°F) interrupting the blower motor operation in all speeds except HI.
- The thermal limiter cannot be reset and is not serviceable.
The blower speed control is located on the evaporator housing in the engine compartment.
- The function of the blower motor speed control is to convert low power signals from the electronic automatic temperature control module to a high current, variable ground feed for the blower motor (18527).
- The blower motor speed is infinitely variable and is controlled by the electronic automatic temperature control module software.
- A delay function provides a gradual increase or decrease in blower motor speed under all conditions.