A leading cause of failure in fitness equipment is insufficient power to the internal components of a machine or no power at all. Knowing the basics of using a multimeter will be a great help in your troubleshooting efforts.
How to Use a Multimeter for Electronic Testing
Digital multimeters come in a variety of forms for use in electronic testing. For most situations be sure your multimeter can handle:
- DC and AC volts
- AC and DC current
Manual range meters are the most common, but auto range meters are easier to use. You need to set your meter to the correct setting, on manual range meters. The scale will adjust automatically to the necessary range for the values you wish to measure, on auto range meters.
If your multimeter has settings or symbols different to the ones we discuss, consult your owner's manual to verify its ability to test the circuit you want to test.
You need to know what circuit you are testing and the value you want to verify. Otherwise, you may damage the circuit or your meter. Never touch the exposed metal part of the probes or any metal surface that may be carrying a charge.
Continuity is a good way to test for any shorts in a circuit. Continuity testing shows whether there is or is not a complete connection. To indicate a connection, the meter will indicate:
- “beep” and/or any value other than 1 on left of display.
- no beep and/or 1 on left of display
This test should be done while the circuit is disconnected from any source of power. Be sure the red lead is plugged into the continuity socket. If your meter doesn't have a continuity socket, use the Ohms socket. The black lead should go into the Com socket. Some meters only have two sockets. Connect Black to the Com socket, and connect Red to the other socket.
If you cross the leads, the meter will show a low value or beep. This means there is continuity. It does not rule out the possibility of shorts.
EXAMPLE: If you have a piece of wire that you want to test for breaks, this can be done easily using the continuity meter, you can test for breaks by touching each end of the wire with a probe.
Suppose that same piece of wire is a wire loom, meaning several pieces of wire are inside the same insulator. You can use your continuity meter to check that the wires are continuous. You can also check for any shorts by touching both ends of any conductor. Touch both ends of each wire with your probes. You should hear a single beep or see a value displayed.
- No beep & no value = circuit is not continuous
- Beep & value = a short
To test for resistance; be sure the Red lead is in the Ohms socket, the black lead is in the Com socket, and the meter is set to Ohms.
IMPORTANT: test the resistor with one end disconnected from any circuits.
Testing for DC Volts
- Connect the black lead to the Com socket
- Connect the red lead to the Voltage socket
- Set the dial to DC voltage (one range above value you are checking for)
- Do not to cross the leads - it will short the circuit
If you get a zero reading, check the setting on your meter, as it may be set to AC.
You can check voltage without disconnecting it from the machine if you have a battery installed. To do this, probe the positive and negative ends on the battery.
Testing AC Volts
Set your meter to the AC Volt setting and range (one range above the reading you’re looking for). Insert the red lead in the “V” socket, and the black probe in the “Com” socket.
Do not short the leads during testing. It will short the circuit and may damage your meter.