Testing For Electrical Intermittents

Use the following procedure to detect an intermittent circuit that is currently operating normally.

Important: The J 39200 must be used to perform the following procedure since the DMM can monitor current, resistance or voltage while recording the minimum (MIN), and maximum (MAX) values measured.

1. Connect the J 39200 to both sides of a suspected connector, (still connected) or from one end of a suspected circuit to the other.

Important: Refer to Troubleshooting with a Digital Multimeter

2. Select the appropriate voltage mode on the DMM.
3. Press the Range button to select the desired voltage range.
4. Press the MIN MAX button. The DMM displays 100 ms RECORD and emits an audible tone (beep).

Important: The DMM is now ready to record and generates an audible tone for any change in voltage.

The 100 ms RECORD mode is the amount of time used to record each snapshot of information used for calculating the AVG voltage.
5. Simulate the condition that is potentially causing an intermittent connection, either by wiggling the connections or the wiring, also by test driving or performing other operations. If an open or a high resistance condition is created voltage is present and the DMM emits a tone for as long as the condition exists.
6. Press the MIN MAX button once to display the MAX value and note the value.
7. Press the MIN MAX button twice for the MIN value and note the value.
8. Determine the difference between the MIN and MAX values.
- If the variation between the recorded MIN and MAX voltage values is one volt or greater an intermittent open or high resistance condition exists. Repair condition as necessary.
- If the variation between the recorded MIN and MAX voltage values is less than one volt an intermittent open or high resistance condition does not exist.