General

The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter.

These meters are available in two designs: analog (needle-type) and digital (electronic display-type).

NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device.

Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent).