Test meters come in a variety of models. Any working model will be adequate for simple tests. However,
accurate readings are important. Make sure the test meter is of high quality. The Fluke 88 Digital Multimeter (DMM) is recommended because it has very little current and a high impedance (resistance) of 10 megaohms (10 Mฮฉ).
CAUTION: Only use a high impedance digital multimeter when troubleshooting an electronic circuit.
Do not use any kind of battery powered test light. Battery test lights can damage an electronic control circuit.
NOTE: Some devices in an electronic control system are not capable of carrying an appreciable amount of
current. Therefore, test equipment must be designed to not damage any part the electronic control system. Do not use analog meters unless specified. Analog meters use too much current to test an electronic control system.