TB 9-2320-360-13&P-1
UNIT TROUBLESHOOTING INTRODUCTION - CONTINUED
0014 00
(4)
Observe warnings, cautions, and notes. The formatting and symbols used in this manual for warnings, cau-
tions, and notes are as follows:
WAR N I N G
This is the symbol for a warning statement. If you see the word WARNING above a question on the left-
hand page, look on the right-hand page for the text of the message. WARNINGS describe a situation which
could cause severe injury or death to personnel.
CAU T I ON
This is the symbol for a caution statement. If you see the word CAUTION above a question on the left-hand
page, look on the right-hand page for the text of the message. CAUTIONs describe a situation which could
cause damage to equipment.
N OT E
This is the symbol for a note. Notes are located directly above the test to which they refer. Notes provide
additional information for performing a test.
c.
Measurements Required for Troubleshooting.
CAU T I ON
Use proper-sized multimeter test leads and ensure care is used when checking for resistance, continuity, or
voltage at connectors or damage to equipment may result.
(1)
Resistance measurements.
(a) Connect red test lead to volt-ohm input connector and black lead to COM input connector on meter.
(b) Set the function/range switch to the desired ohm position. If the magnitude of the resistance is not
known, set the switch to the highest range, then reduce until a satisfactory reading is obtained.
(c) If the resistance being measured is connected to a circuit, turn ENGINE switch OFF.
(d) Connect test leads to the circuit being measured. When measuring high resistance, be careful not to
contact adjacent points, even if they are insulated. Some insulators have a relatively low insulation
resistance which can affect the resulting measurement.
(e) Read the resistance value on the digital display.
(f) Continuity checks.
(g) Place the function/range switch in any ohm range.
(h) Some meters show "l+m", or simply "l" when functioning/range switch is in any ohm position.
(i) Connect the red test lead to the volt-ohm connector and black lead to COM input connector on the
meter. When the test leads are separated or measuring an out-of-range resistance, the digital display
will indicate "OL" (Over Limit).
(j) Put one test probe at one end of the wire or circuit to be tested. Use the other test lead to trace the cir-
cuit. When continuity is established, an ohm symbol will appear in the upper left corner of the digital
display. If contact in the wire is maintained long enough (about 1/4 of a second), the OL will disappear
and the resistance value of the wire or circuit will appear next to the symbol.
(k) If your multimeter does not work in this manner, learn how it operates before performing trouble-
shooting.
0014 00-2
