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4-13. Ground Test
This function is designed to locate bad
grounds , volt age drops, intermi ttent
c onnec tions, or any sourc e of high
res ist anc e in automoti ve elect rical
circuits and grounds.
I t provides a very efficient check of a
vehicle’s electrical system condition.
T his tes t work s by measuri ng t he
voltage drop across any cable to which
it is connected. The amount of voltage
drop is displayed as “ ”, “ ”,
“ ”, and “ ” annunciators in the
secondary display.
1.
Set rotary selector to Elec position.
2.
Press menukey 2 to select Ground
Test function. “
” is displayed in
the primary display and “ ” is
displayed in the secondary display.
3.
Insert black lead into COM terminal
and red lead into Elec terminal.
4.
Connect t he two probes t o t he
cable being t est ed. A good
connect ion is indic ated by t he
display of “ ” in the secondary
display.
5.
Apply power t o the vehicle. The
condition of the cable between the
two probes is indicat ed by either
“ ”, “ ”, or “ ” in the
secondary display.
If either “ ” or “ ” is displayed, check the cable closely for poor connections
between the two test leads.
Make certain all connectors are clean and secure.
NOTE: When checking ground connecti ons, always clean or scrape off the
area of the chassis where the ground lead is being connected. Dirt,
grease, and paint are insulators and will prevent the unit from making
a good connection. If a ground connection is suspect, connect the
uni t to the chassis as close as possi ble. When testi ng chargi ng or
starting circuits from the battery, always make the first connection to
the battery post, and not the battery connector . Corrosion on the
battery post and connector surfaces can be the source of the problem
very frequently.
SECONDARY DISPLAY
(Good)
(Suspect)
(Bad)
(Open)
PRIMARY DISPLAY (Amount of Voltage Drop)
< 0.1999 V
0.2000 ~ 0.3999 V
0.4000 ~ 1.9999 V
2.0000 V
