1. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
2. Verify that the drive belt auto tensioner moves smoothly in the operational direction.

3. Turn the drive belt auto tensioner pulley by hand and verify that it rotates smoothly.
4. Install the drive belt. (See DRIVE BELT REPLACEMENT.)
Drive belt replacement
Valve clearanceMazda 6 Service Manual: Thermostat
THERMOSTAT REMOVAL/INSTALLATION
1. Remove the plug hole plate.
2. Disconnect the negative battery cable.
3. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS.)
4. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
5. Remove the washer tank.
6. Remove the P/S oil pump.
Note
...
Mazda 6 Service Manual: Cruise actuator inspection
1. Disconnect the cruise actuator connector.
2. Measure the voltage, continuity and resistance at the cruise actuator
terminals as indicated below.
If not as specified, inspect the parts listed under Action.
If the parts and wiring harnesses are okay but the system still does not
work pr ...