7.4 Fuses
Note: With the power OFF, always remove a fuse from its
socket before testing it. With mini, maxi, or cartridge fuses,
touch the test leads to each end of the fuse (see fig. 9 & 10).
If the fuse is good, the display should read -0- ohms. If the
display doesn't change at all, replace the fuse. On plug-type
fuses, touch the test lead on the bottom contact and the other
on the threaded metal contact (see fig. 11). On time-delay/
tamper-proof fuses, the other metal contact is at the top of the
ceramic threads.
Figure 10
Figure 9
7.5 Switches
Cut off the power source to the switch. If necessary,
remove the switch. Turn the switch to the ON position and
touch the test leads to the switches terminals (see fig. 12). If
the switch is good, the display should read -0- ohms. If the
display doesn't change at all, replace the switch. On other
than two-way SPST (single pole, single throw) switches such
as three-way light switches or double pole double throw
(ON-OFF-ON) switches, in each ON position you will need to
alternate the test leads between the switches terminals to
determine which two terminals control that ON position.
7.6 Heating Elements
Household appliances such as coffee makers and water
heaters contain heating elements which may require
troubleshooting. When making continuity checks on heating
elements, disconnect the element(s) from the circuit(s) that
supply it/them. Touch the test leads, one on each end of the
Figure 11
Figure 12
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element and observe the display. The reading should indicate
low ohms. If the display doesn't change, the heating element
may be broken. If the element(s) show that continuity exists,
test for continuity of the circuit(s) that feed the element(s).
7.7 Thermostats
Make sure the thermostat control is in the OFF position.
Remove the thermostat cover. Touch the test leads to the
contact points on the thermostat. The display should read -0-
ohms. If not, either one of the contacts may be loose or broken.
8. Diode Check
Diodes should be tested with both forward and reverse
voltages applied:
1) Plug the red (+) test lead into the (+) input jack, and the
black (-) test lead into the COM input jack. Set the
function/range switch to the diode test setting (
2) Touch the test leads to the diode, one lead on the anode
and the other on the cathode. The indication of a diode in
good condition is a low resistance reading when the red
lead (+) is on the anode and the black (-) lead is on the
cathode. When the test leads are reversed (reverse voltage
is being applied), the meter should display a
"1" on the left side of the display if the diode is good.
NOTE: A low resistance in both directions indicates a
shorted diode; a high resistance in both directions indicates
an open diode. In either case the diode is defective and
should be replaced.
9. Battery Replacement
1) Remove the screws in the back cover of the tester and
carefully separate the back cover from the front.
2) Note the polarity of the battery terminals when removing it
from its connector and replace.
3) Carefully replace the back cover and tighten the screws.
Do not overtighten the screws as this may strip the threads
in the tester housing.
).
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