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: Front door speaker inspection
1. Inspect for resistance between the front door speaker terminals using an
ohmmeter.
If not as specified, replace the front door speaker.
2. To verify that the front door speaker outputs sound, apply voltage to the
front door speaker and release using a 1.5-V battery.
If not outp ...
Mazda 6 Service Manual: Troubleshooting procedure
Basic flow of troubleshooting
DTC troubleshooting flow (on-board diagnostic)
Diagnostic trouble codes (DTCs) are important hints for repairing
malfunctions that are difficult to simulate.
Perform the specific DTC diagnostic inspection to quickly and accurately
diagnose the malfunction.
The ...