1. Measure the temperature around the water temperature sensor.
2. Measure the resistance between terminals of the water temperature sensor.

Water temperature sensor removal/installation
Refrigerant pressure switch removal/installationMazda 6 Service Manual: Rear Window Defogger
The rear window defogger clears fog from the rear window.
The ignition must be switched ON to use the defogger.
Press the switch to turn on the rear window defogger. The rear window defogger
operates for about 15 minutes and then turns off automatically.
The indicator light illuminates when the ...
Mazda 6 Service Manual: Cruise control switch inspection
1. Disconnect the negative battery cable.
2. Remove the driver-side air bag module. (See DRIVER-SIDE AIR BAG MODULE
REMOVAL/INSTALLATION.)
3. Disconnect the cruise control switch connector.
4. Inspect for resistance and continuity between the cruise control switch
terminals using an ohmmeter. ...