Use the following procedure to detect intermittent terminal contact or a broken wire with an intermittent connection inside the insulation.

The J 39200 Digital Multimeter (DMM) can monitor current, resistance, or voltage while recording the minimum (MIN) and maximum (MAX) values measured. The DMM can also be set to display the average (AVG) value measured.

When diagnosing circuits that have voltage applied, use the voltage setting to monitor a connector (or length of a circuit) which is suspected of having an intermittent connection but is currently operating normally.

1. Connect the J 39200 Digital Multimeter to both sides of a suspect connector (still connected) or from one end of a suspect circuit to the other. This will continuously monitor the terminal contacts or length of wire being checked. Refer to Meter Connections for examples of the various methods for connecting the DMM to the circuit.
2. Set the DMM for voltage. Since the MIN MAX mode does not use auto ranging, manually select the voltage range necessary before proceeding.
3. Press the MIN MAX button. The DMM should read 100 ms RECORD (100 millisecond record) and emit a 1/4 second beep. The DMM is now ready to record and will generate an audible tone for any change in voltage. At this point, you may wish to press the PEAK MIN MAX button, which will record any voltage variations that occur for at least 1 millisecond.
4. Try to simulate the condition that is potentially causing an intermittent connection, either by wiggling connections or wiring, test driving or performing other operations. If an open or resistance is created, a voltage will be present and the DMM will emit a tone for as long as the open or resistance exists. Any change in voltage will cause the DMM to emit a tone for no less than 1/4 second. (Listening for a tone while manipulating wiring is very helpful for narrowing down an intermittent connection.)

Use the MIN and MAX values when the DMM is out of sight or sound range, in noisy areas or for test driving when it may not be possible to monitor the DMM.

To check the MIN and MAX recorded voltages press MIN MAX once for MAX and twice for MIN. A variation between MIN and MAX recorded voltages (unless nearly 0 volts) suggests an intermittent open or that resistance exists and should be repaired as necessary.

Important: The 100 ms RECORD (100 millisecond record) mode is NOT the amount of time allowed to perform a specific procedure. It is the amount of time used to record each snapshot of information used for calculating AVG when in the MIN MAX mode.

Digital Multimeter (DMM) Connections

The previous diagnostic procedure was written to detect intermittents using the DMM set to voltage. Whether using the current, voltage, or resistance setting to detect intermittents, it is necessary to connect the DMM to the circuit.

Following are examples of the various methods of connecting the DMM to the circuit to be checked:

Notice: Do not touch the electrical connections and pins. Do not allow the pins or connections to contact brake fluid. This will damage the EBCM.

Notice: Do not touch the electrical connections and pins. Do not allow the pins or connections to contact brake fluid. This will damage the EBCM.

Continuity tests that work well for detecting intermittent shorts to ground can be performed by setting the DMM to ohms, then pressing the PEAK MIN MAX button. An audible tone will be heard whenever the DMM detects continuity for at least 1 millisecond.

The J 39200 Instruction Manual is a good source of information and should be read thoroughly upon receipt of the DMM as well as kept on hand for reference during new procedures.