Blower Control

The Blower may only run if the ignition is on. There is a 0.5 second delay after engine cranking to energize the blower. This delay is controlled by the BC1. The BC1 receives the end of cranking (engine started) signal from the EMS2000. After a 0.5 second delay the BC1 energizes the Blower Relay. The Blower Relay supplies power to the 5 position blower switch (Off, 1, 2, 3, 4). Activation of the blower switch creates a power flow through the resistor pack (except in position 4). The varying voltage from the resistor pack is supplied to the blower and the BC1. The blower speed is based on the voltage supply from the resistor pack. Less resistance means higher voltage and higher blower speed. The BC1 looks for the blower speed voltage before requesting the AC compressor. Loss of blower voltage will result in loss of compressor.