2002 Ford Explorer replaced the auto temp climate fan resistor
If you get no fan speed at all on any of the positions except high then it is a sure sign the resistor is bad. On the high position no resistance is supplied by the resistor and the current flows unrestricted to the motor. If you can take the system out of auto temp mode try that. Also, use an multi meter and check for voltage to the resistor at each of the fan settings manually. If there is no current supplied at the lower settings the selector switch is bad.
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