Pulse Width Modulator (PWM)
WARNING: This page is about a different car, the 1994 Lincoln Mark VIII. However, it is still accessible from the selected car via links, so may be relevant.
Pulse width modulator supplies variable control voltage to A/C blower motor. This provides variable blower speeds. PWM is incorporated in Blower Speed Controller (BSC) and is not serviced separately. PWM includes protection circuitry to turn off the output during a high voltage condition.
NOTE:
Temperature control lock-out valve and switch assembly may also be referred to as Cold Engine Lock-Out (CELO) switch.