HVAC - Air Conditioning System
Blower Motor Controller InspectionReference: Blower Motor Controller Removal and Installation:Automatic Type
1. Check internal circuit of controller for resistance as follows.
a. Measure resistance between "1" terminal and "2" terminal of blower motor controller.
Blower motor controller resistance
"1" - "2": approximately 10 kohms
If resistance does not meet above specification, replace blower motor controller.
b. Using ohmmeter, connect its positive terminal to "3" terminal of blower motor controller and negative terminal to "1" terminal of blower motor controller and check that there is no continuity.
2. Check controller for operation as follows.
a. Using bulb (3.4 W) (5) and service wire, connect battery positive terminal to "3" terminal of blower motor controller as shown figure.
b. Using service wire, connect battery negative terminal to "1" terminal of blower motor controller.
c. Arrange 3 new 1.5 V batteries (6) in series (check that total voltage is 4.5 - 5.0 V) and connect its positive terminal to "2" terminal of blower motor controller and negative terminal to "1" terminal of blower motor controller.
Then, check that bulb lights. If bulb does not light under the above conditions, replace blower motor controller.