Testing for Electrical Intermittents: Testing
If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM. This feature allows you to manipulate the circuit without having to watch the J 39200 . The J 39200 will generate an audible tone when a change is detected.
NOTE:
The J 39200
must be used in order to perform the following procedure since the J 39200
can monitor current, resistance or voltage while recording the minimum (MIN), and maximum (MAX) values measured.
- Connect the J 39200 to both sides of a suspected connector (still connected), or from one end of a suspected circuit to the other. Refer to Troubleshooting with a Digital Multimeter for information on connecting the J 39200 to the circuit.
- Set the rotary dial of the J 39200 to the V (AC) or V (DC) position.
- Press the range button of the J 39200 in order to select the desired voltage range.
- Press the MIN MAX button of the J 39200
. The J 39200
displays 100 ms RECORD and emits an audible tone (beep).NOTE: The 100 ms RECORD mode is the length of time an input must stay at a new value in order to record the full change.
- Simulate the condition that is potentially causing the intermittent connection, either by wiggling the connections or the wiring, test driving, or performing other operations. Refer to Inducing Intermittent Fault Conditions .
- Listen for the audible Min Max Alert which indicates that a new minimum or maximum value has been recorded.
- Press the MIN MAX button once in order to display the MAX value and note the value.
- Press the MIN MAX button again in order to display the MIN value and note the value.
- Determine the difference between the MIN and MAX values.
- If the variation between the recorded MIN and MAX voltage values is 1 V or greater an intermittent open or high resistance condition exists. Repair the condition as necessary.
- If the variation between the recorded MIN and MAX voltage values is less than 1 V, an intermittent open or high resistance condition does not exist.