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7-10
E
–
+
ELEC
ELECTRICAL ANALYSIS
Low resistance measurement
NOTE:
• When measuring a resistance of 10
Ω
or less
with the digital tester, the correct measure-
ment cannot be obtained because of the
tester’s internal resistance.
• To obtain the correct value, subtract the
internal resistance from the displayed mea-
surement.
• The internal resistance of the tester can be
obtained by connecting both of its terminals.
Correct value =
Displayed measurement –
Internal resistance
Peak voltage measurement
NOTE:
• When checking the condition of the ignition
system it is vital to know the peak voltage.
• Cranking speed is dependant on many fac-
tors (e.g., fouled or weak spark plugs, a
weak battery). If one of these is defective,
the peak voltage will be lower than specifica-
tion.
• If the peak voltage measurement is not
within specification the engine will not oper-
ate properly.
• A low peak voltage will also cause compo-
nents to prematurely wear.