Measuring Resistance; Howt Omeasure Resistance Using An Ohmmeter - Honda Motorcycle Service Manual

ELECTRICAL FUNDAMENTALS
MEASURING RESISTANCE
Along with voltage, resistance is another basic parameter for
diagnosing circuits and their components.
Resistance is measured for the following reasons.
a
To check if components are working properly:
The resistance value of a coil leg. ignition coil) indicates if it
is normal or malfunctioning.
@ T o check for a broken wire.
A continuity check indicates if a wire is intact or broken.
CHECKING COIL
CHECKFORBROKEN
WIRES(0PEN CIRCUIT)
How
t o
measure resistance using an ohmmeter
NOTE
.
Proper zeroing of an analog ohmmeter is necessary to
obtain correct measurements. Touch the t w o probes
together and adjust the ohmmeter so that it registers 0
( a ) .
For a digital ohmmeter, note the resistance when
you touch the t w o leads together, and subtract this
amount from your meter reading.
.
~ ~ d o
OHM ADJUSTER
Since the polarity of the terminals is not important, either
probe may be applied to either terminal. However, since
diodes allow current t o flow in onedirection only,the polarity
is important when checking diodes.
Unlike when measuring voltlage,
it
is necessary to disconnect
the component from the circuit. If resistance is measured with
the entire circuit connected, the ohmmeter will read a
different resistance than it should.
GOOD
Date of Issue
:
March, 1995
0
HONDA IWOTOR CO.,LTD.
BAD
Similarly, if a circuit has branches the connector leading t o the
specific branch needs to be disconnected in order t o read
resistance correctly.
WITH CONNECTOR CONNECTED-----R
=
ELLEL
WITH CONNECTOR R1
+
R2
DISCONNECTED-
R
=
R1