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: Intake-air system removal/installation
Warning
When the engine and intake-air system are hot, they can badly
burn. Turn off the engine and wait until they are cool before removing the
intake-air system.
Fuel vapor is hazardous. It can easily ignite, causing serious
injury and damage. Always keep sparks and flames away from ...
Mazda 6 Service Manual: Saving Fuel and Protection of the Environment
How you operate your Mazda determines how far it will travel on a tank of fuel.
Use these suggestions to help save fuel and reduce CO2.
Avoid long warm-ups. Once the engine runs smoothly, begin driving.
Avoid fast starts.
Drive at lower speeds.
Anticipate when to apply the brakes (avoid ...