TROUBLESHOOTING & DIAGNOSTICS
Read all of this manual to become thoroughly familiar with this vehicle. Pay particular attention to all Notices, Cautions, Warnings, and Dangers.
Page O-24
Repair and Service Manual
DIGITAL VOLT OHM METER
A typical DVOM (digital volt ohm meter) is shown. A recommended model is available through the Service Parts Depart-
ment as P/N 27481-G01. For the purpose of this section, the red probe (+) and black probe (-) are used. Any DVOM may
be used, however the controls, displays, accuracy and features may vary depending on the make and model. Always fol-
low the meter manufacturer’s recommendations and instruction for the use and care of the meter.
Fig. 1 DVOM
TROUBLESHOOTING
In order to effectively troubleshoot the circuits that include the horn, lighting, brake/turn signals and gauges, the techni-
cian must be able to use the wiring diagram and a DVOM.
The wiring diagram shows the path followed by voltage or a signal from its origination point to its destination. Each wire is
indicated by color.
The technician should use simple logic troubleshooting in order to reduce the number of steps required to isolate the
problem.
Example 1: If the vehicle will not start or none of the lights function (or burn dimly) the battery should be tested before try-
ing to troubleshoot the lighting circuit.
Example 2: If a problem occurs in the lighting circuit that results in only one of the headlights not working, there is no rea-
son to check battery wiring or the fuse since it is obvious that voltage is present. Since bulbs will burn out over time, the
obvious place to start is at the headlight that is not functioning. if power is present at the connector and the ground wiring
is satisfactory, the only possibilities that exist are a burned out bulb or a poor contact between the connectors and the
headlight.
If power is not present but the other headlight functions, a wiring problem is indicated between the two headlights.
In some cases where battery voltage is expected, the easiest way to test the circuit is to set the DVOM to DC volts and
place the negative (-) probe of the DVOM to the negative battery terminal. Move the positive (+) probe to each wire termi-
nation starting at the battery and working out to the device that is not working. Be sure to check both sides of all switches
and fuses.
When no battery voltage is found, the problem lies between the point where no voltage is detected and the last place that
voltage, was detected. In circuits where no voltage is expected, the same procedure may be used except that the DVOM
COVER
DATA-H
SWITCH
RANGE
SWITCH
TRANSISTOR
SOCKET
+ TEST LEAD
- TEST LEAD
TEST RECEPTACLES
FUNCTION SELECTOR
SWITCH
CONTINUITY TEST
DIODE TEST, AC/DC
CURRENT TOGGLE
SWITCH
DIGITAL DISPLAY
