Power Probe ECT 2000 - Manual (Page 23)

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How to Trace out an Open Circuit:
An open circuit does not complete a path to ground. The cause for an open circuit can vary from an open switch, unplugged connector, bad con-
nections and breaks in wires.
1. Connect the SMART transmitter’s power lead to the vehicle’s battery.
2. Connect the SMART transmitter’s signal lead to the open circuit.
3. Turn on the SMART receiver. It will be in “pulse mode”.
4. Place the “Open & Short Pick-Up” near and parallel to the open wire until the “Open Circuit” LED indicator blinks and beeps. (be careful to
hold the SMART receiver from the outer edge to prevent your hand from shielding the signal)
5. Lift the SMART receiver away from the open circuit so that the pulse of the “Open Circuit” indicator slows down but doesn’t stop completely.
6. Press the “Power/Sensitivity Lock” button.
7. Hold the SMART receiver near to the open circuit and while the “Open Circuit” indicator is ON steady, follow the path of the circuit or wire
until you loose the signal.
8. If you reach an obstacle, remove it or work through it. Remember to ISOLATE THE CIRCUIT YOU ARE TRACING. Inspect the circuit and
verify the open circuit. (See” “Verify an Open Circuit” below.)
9. Continue Steps 7-8 until you fi nd the open or break in the circuit.
Verify an Open Circuit:
One of the best methods for verifying an open circuit is using the Power Probe III circuit
tester together with the SMART transmitter. Since the SMART transmitter’s open circuit
signal delivers 8 volts and a 4 kHz signal, it can be easily detected by directly contacting
the Power Probe III to the wire of the transmitting circuit.
Contact the probe of the Power Probe III to the open circuit with the open circuit signal
applied to it. You should hear the 4 kHz tone from the Power Probe III speaker. If you
don’t hear the 4 kHz tone, inspect the circuit closer to determine why? If you hear the 4
kHz tone, you are on the correct circuit.Testing the open circuit with SMART transmit-
ter together with the PP3 has advantages over just a continuity test. This is because the
SMART transmitter’s toggle tone feature will alert you if the open circuit makes contact
with an intermittent grounded circuit. (See: “Circuit Wiggle & Flex Test” pg. 26)
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