GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Power and Signal Distribution 🢒 Wiring Systems and Power Management 🢒 Measuring Voltage

Caution: Refer to Test Probe Caution in the Preface section.

The following procedure measures the voltage at a selected point in a circuit.

  1. Disconnect the electrical harness connector for the circuit being tested, if necessary.
  2. Enable the circuit and/or system being tested. Use the following methods:
    3. • Turn ON the ignition, with the engine OFF.
    • Turn ON the engine.
    • Turn ON the circuit and/or system with a scan tool in Output Controls.
    • Turn ON the switch for the circuit and/or system being tested.
  3. Select the V (AC) or V (DC) position on the DMM.
  4. Connect the positive lead of the DMM to the point of the circuit to be tested.
  5. Connect the negative lead of the DMM to a good ground.
  6. The DMM displays the voltage measured at that point.