User Manual

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WARNING : With this function, if you are contacting a protected circuit, a vehicle’s
fuse can be blown or tripped if you apply ground to it.
3.8 Checking for Bad Ground Contacts
Probe the suspected ground wire or contact with the probe tip.
Observe the green LED. Depress the power switch forward then release. If the green
LED went
out and the red LED came on, this is not a true ground..
If the circuit breaker tripped, this circuit is more than likely a good ground. Keep in
mind that high current components such as starter motors will also trip the circuit
breaker.
3.9 Following & Locating Short Circuits
In most cases a short circuit will appear by a fuse or a fusible link blowing or an
electrical protection device tripping (i.e., a circuit breaker). This is the best place to
begin the search.
 Remove the blown fuse from the fuse box.
 Use the probe tip to activate and energize each of the fuse contacts. The contact which
trips the circuit breaker is the shorted circuit. Take note of this wire ’ s identification
code or color.
 Follow the wire as far as you can along the wiring harness.
Here is an example for this application.

If you are following a short in the brake light circuit, you may know that the wire must
pass through the wiring harness at the door sill. Locate the color-coded wire in the
harness and expose it.

Probe through the insulation with the probe tip, and depress the power switch forward
to activate and energize the wire.

If the circuit breaker tripped, you have verified the shorted wire. Cut the wire and
energize each end with the probe tip. The wire end which trips the circuit breaker
again is the shorted circuit and it will lead you to the shorted area.

Follow the wire in the shorted direction and repeat this process until the short is
located.