4. Connect the test probes to the circuit: black to the negative polarity test point (circuit ground), red to positive test point. Note: Most modern DMMs automatically detect polarity. When measuring dc voltage, it is not critical for the red lead to contact a positive terminal or black to touch negative.
http://en-us.fluke.com/training/training-library/test-tools/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter.html
To check: 1  Disconnect one spark plug wire: Grab the wire's boot and carefully twist the boot back and forth as you pull it off the spark plug. If you can't reach the boot, use a set of spark plug wire pliers. 2  Do the same at the other end of the wire. 3  Wipe the wire clean using a rag to remove any dirt, grease. and oil.
https://axleaddict.com/auto-repair/Checking-spark-plug-wires-using-two-simple-strategies
Measuring Voltage. To start, let’s measure voltage on a AA battery: Plug the black probe into COM and the red probe into mAVΩ. Set the multimeter to “2V” in the DC (direct current) range. Almost all portable electronics use direct current), not alternating current.
https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/measuring-voltage
AC and DC Voltage Measurements. 1  In some applications, dc voltage measurements may be taken in circuits that include ac voltage. 2  To ensure maximum accuracy of a dc voltage measurement, first measure and record the ac voltage. 3  Some DMMs can simultaneously measure and display the ac and dc components of a signal.
http://en-us.fluke.com/training/training-library/test-tools/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter.html
This test will check your wires' insulation for voltage leaks. 1  Connect one end of a jumper wire to a screwdriver metal shank. 2  Then, connect the other end of the jumper wire to a metal bracket or screw on the engine to ground the screwdriver. 3  Set the emergency brakes on your vehicle, start the engine, and let it idle.
https://axleaddict.com/auto-repair/Checking-spark-plug-wires-using-two-simple-strategies
Before throwing away an appliance, test it with a multimeter. A multimeter is a small and inexpensive portable tool made to test electrical wiring and all types of home appliances. 1. Unplug any appliance you need to test and turn off the power from the circuit breaker to eliminate risk of electric shock. Turn on the multimeter and set its function to the lowest setting for ohms (resistance). If you are using an analog device, hold the two probes together as you adjust the meter’s needle to “0.”. Attach alligator clips to the multimeter probes. Access the appliance element you want to test.
http://homeguides.sfgate.com/check-appliances-multimeter-33566.html
The most common use of this setting is to test remaining battery voltage, alternator output, power to a car radio, amplifier, etc. AC Voltage (V~ with a wavy line): In the meter pictured, AC Volts is written, not expressed as a symbol. This meter has a 200V setting and a 750V setting.
http://knowledge.sonicelectronix.com/car-audio-and-video/accessories-and-installation/how-to-use-a-multimeter/
You may have seen a multimeter being used by your local electrician or even a stereo installation shop. This universal tool is a must-have in all homes for many reasons. You do not need to have a degree in Electrical Engineering to find a use for a multimeter, also known as a volt/ohm meter (VOM). A VOM is an electronic measuring device that combines several different measurement functions into one handheld, easy to use device.
http://knowledge.sonicelectronix.com/car-audio-and-video/accessories-and-installation/how-to-use-a-multimeter/
For this test, use a simple analog or digital ohmmeter. 1  Set your meter to the ohms scale and to a setting that will let you read 50,000 ohms or above. 2  Measure the length of the wire you want to read first using the tape measure, and make a note of the length in feet on a piece of paper.
https://axleaddict.com/auto-repair/Checking-spark-plug-wires-using-two-simple-strategies
If the voltage measurement falls within the range of a lower setting, follow these steps: 1  Disconnect the test probes. 2  Change the dial setting to [mV dc symbol]. 3  Reconnect the test probes and read the measurement.
http://en-us.fluke.com/training/training-library/test-tools/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter.html
what setting do i need to put my meter at to test a plug
Set the multimeter to “2V” in the DC or direct current range. To test a plug put meter at “2V” in the Direct Current range.