Triplett Hound 3 – PN: 3392 - Manual (Page 32)

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technique. Have an assistant position the open fault while
you are out of the room, and then cover the wire with card-
board, newspaper, plywood, etc. . . . and see if you can find
the open. You’ll probably find that the open is sometimes
found in the wrong place. Notice what wire configuration
causes this to happen and experiment with the nulling and
grounding techniques to see if a method can be figured out
that will work in these situations.
To test the actual resistance heating circuit, disconnect the
ends of the heating wires from the power source. This can
usually be done at the thermostat that controls the room.
Attach the clips of the FOX or FOX 2 to the wires (one clip to
each wire) and use the nulling and grounding techniques
discussed above, and any other methods learned from your
experiments, to find the open fault.
7.2.8: Cars
Wires can be traced in cars or similar metal bodied vehicles
using the grounded method. The metal body of the car acts
as a ground, and as a shield. This means that, compared to
tracing in a wood frame structure, it will be necessary to
place the HOUND 3 closer to the target wire to pick up a
tracer tone.
Connect one clip of the FOX or FOX 2 to the metal chassis of
the car, and the other clip to the wire to be traced. As in
other applications, the far end of the wire must be discon-
nected from any loads or any other wires, or the tracer tone
will be shorted out, or it will migrate into other wires. Be-