Blower Motor Speed Control

WARNING: This page is about a different car, the 2002 Lincoln Blackwood. However, it is still accessible from the selected car via links, so may be relevant.

The A/C blower motor speed control is a Pulse Width Modulated (PWM) type which provides variable blower speed control of blower motor. A/C blower motor speed control is controlled by switching control signal voltage of 5 volts OFF and ON 2,000 times per second. By varying ratio of time on (5 volts) to time off (0 volts), EATC module tells A/C blower motor speed control how fast blower motor should run.

The A/C blower motor speed control has circuitry to protect blower motor from burning out in event of a locked rotor condition. It can compensate for changes in battery positive voltage which prevents blower speed from slowing down when engine is idling and will provide up to a maximum of 30 amps for blower motor operation with battery voltages between 10 and 16 volts.