Jumper wire
Caution

Voltmeter
is used by connecting the positive (+) probe (red lead wire) to the point where voltage will be measured and the negative (-) probe (black lead wire) to a body ground.

Ohmmeter
Caution

Connectors
Precautions before weldingMazda 6 Service Manual: Rear door speaker removal/installation
1. Disconnect the negative battery cable.
2. Remove the rear door trim.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Rear Door Speaker Installation Note
Attach the speaker with the wiring harness placed in the groove of the door
unit panel.
...
Mazda 6 Service Manual: Rear wiper motor inspection
1. Disconnect the negative battery cable.
2. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
3. Disconnect the rear wiper motor connector.
4. Connect battery positive voltage to the rear wiper motor terminal A and
the ground to a bare metal part of the vehicle a ...