1. Connect the connector to the running light unit.
2. Connect the negative battery cable.
3. Measure the voltage at the running light unit using voltmeter.
4. If the value are not as specified in the Terminal Voltage List (Reference), inspect the parts under Action and related wiring harnesses.
5. If the system does not work properly even though the parts or related wiring harnesses do not have any malfunction, replace the running light unit.
Terminal Voltage List (Reference)



Running light unit 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: Hold switch inspection
Operating Inspection
1. Turn the ignition switch to ON (engine OFF).
2. Verify that the HOLD indicator light is not illuminated. Depress the HOLD
switch and verify that the HOLD indicator light illuminates.
If not as specified, inspect the terminal voltage of the HOLD switch.
Voltage Insp ...