350 Section 3 Fundamentals of Electricity and Electronics
• Place the meter in a secure location. Multime-
ters are expensive, and they can be ruined if
they are dropped. Also keep them away from
moving or hot engine parts.
• Keep the test leads away from hot or moving
parts to ensure that they do not get caught in
engine fans, burned on hot exhaust manifolds,
or suffer other physical damage.
• Use the specifi cations in the service manual to
determine whether a circuit or component is
faulty. Component and circuit resistance, voltage,
and current values vary from model to model.
• If needed, zero or calibrate the ohmmeter before
use to ensure accuracy.
• To help fi nd intermittent problems, wiggle
wires and carefully use a heat gun or freeze
spray on electronic components. This can help
change the reading to indicate the problem.
Figure 22-20. Sample ohmmeter settings and readings. A—The function knob must be set to ohms. B—This reading is displayed in
ohms. C— Note the capital M next to this reading. The reading is displayed in megohms. D—What unit of measurement is used in
this reading?
A
C
B
D
Figure 22-21. Press the Zero button while touching the two
leads together to recalibrate the meter to zero before taking
resistance readings.
Press to
recalibrate
for resistance
readings