To Determine If The Sensor Is Functioning

WARNING: This page is about a different car, the 2005 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.

Start the engine.
Turn the A/C switch on.
Turn the front fan switch on.
Connect the positive (+) and negative (-) probes of the tester 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 below.

If there is any malfunction, inspect on/off points of the thermosensor.

Magnetic clutch	Voltage (V)
On	B+
Off	0

Fig 1: Inspecting Thermosensor Voltage

Courtesy of MAZDA MOTORS CORP.