B
FAULT TESTING
Read all of SAFETY and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
143
Repair and Service Manual
653045
FAULT TESTING
General
To effectively troubleshoot the electrical circuits that
include the headlights, brake light and the information dis-
play, etc, the technician must be able to use the wiring
diagram and a Digital Voltage Ohm Meter (DVOM).
Voltmeter
Before performing any test of wiring
components, disconnect the battery
cables from the battery posts to
prevent electrical shock or explosion. See Battery
Electrical tests of the wiring for continuity may be made
with a DVOM (Digital Volt Ohm Meter). Always follow the
meter manufacturer’s recommendations and instructions
for the use and care of the meter. For the purpose of this
section, the red probe (+) and black probe (-) are used.
Set the meter selector to the ohms scale and check conti-
nuity between each circuit component.
Continuity Check
To prevent possible injury or death
resulting from a battery explosion,
use an insulated wrench and
remove the negative (-) cable from the battery to dis-
connect electrical power to vehicle.
Turn the key switch to the OFF position. Place the direc-
tion selector in the P (park) position before disconnecting
power by removing the negative (-) connection to the bat-
tery.
To check for continuity, set the DVOM to the K
Ω
setting
and select ‘Continuity’. The meter will give an audible
signal when it detects continuity. If the meter does not
have a continuity setting, set it to K
Ω
, the meter will indi-
cate “0” when it detects continuity.
Testing a Switch for Continuity
Place one probe on one contact of the switch, place the
second probe on the second terminal of the switch.
Actuating a normally open (NO) switch will cause the
DVOM to show “0” or give an audible indication when the
switch is operated. A normally closed (NC) switch will
cause the meter to show “0” or give an audible indication
when the probes are attached without activating switch.
The audible indicator will stop and the meter display will
indicate a value greater than “0” when the switch is acti-
vated.
The change in display or audible indicator demonstrates
that the switch is functioning.
Fig. 1 Continuity Check of Switch
Testing the Ignition System
Locate the spark plugs and remove plug boot.
Use a spark plug tester between the plug boot and the
spark plug. Turn the key to engage the starter. A steady
spark should be observed. If spark is not adequate,
inspect the coil and the spark plug wire.
Testing Fuses
Check all the fuses to make sure that components are
properly powered.
If the fuse appears to be blown, replace the fuse.
Press to
Activate
Switch
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