To Determine If The Sensor Is Functioning

Start the engine.
Turn the A/C switch on.
Turn the front fan switch on.
Connect the positive (+) and negative (-) probes of the voltmeter to terminal A and terminal C of the thermosensor respectively. (The wiring harness connector must be connected to the thermosensor connector.)
Inspect the voltage as shown in the figures.
- If not as specified, inspect on/off points of the thermosensor.
  
  Fig 1: Magnetic Clutch Voltage Table
  Courtesy of MAZDA MOTORS CORP.
  
  Fig 2: Measuring Thermosensor Voltage
  Courtesy of MAZDA MOTORS CORP.