Case 580SR, Service Manual

Page: 994 / 1068

166 SECTION 55 - ELECTRICAL SYSTEM
8. COMPONENT TESTING
8.1 GENERAL INTRODUCTION
No special tools are required to remove or replace
electrical components.
Refer to the appropriate section of this Service Manual
for overhaul procedures regarding the starter motor
and the alternator.
Fault finding of electrical systems should be carried out
in a logical and methodical fashion. A few minutes
spent understanding the system and analysing the
symptoms can save considerable time.
An essential piece of equipment for checking electrical
systems is a good quality multimeter with a high imped-
ance which can measure voltage, current and resist-
ance.
NOTE: labelling of connectors prior to disassembly will
greatly assist when reconnecting any harness.
Where it is necessary to clean the multiple connectors,
a contact spray should be used.
IMPORTANT: DO NOT use a cleaner that contains
trichloroethylene which will dissolve the plastic connec-
tors.
The wiring harnesses contain wires which are colour
coded for identification.
Each harness can be removed and replaced, but cer-
tain precautions must be observed:
Z
Disconnect or isolate the battery, negative terminal
first, prior to disconnection or removal of any wiring
harness.
Z
Prior to removal, note the harness routing, clamping
positions and terminal connections.
Z
On replacement, be sure that the harness routing is
not in contact with sharp edges, the exhaust system
or moving parts.
Z
Check connections for wire colour matching.
Z
Use a light coating of di-electrical grease on the con-
nector pins to prevent corrosion.
Z
Be sure that all connectors are fully engaged and no
conductor is exposed.
Z
Tape back unused connectors.
Z
Be sure that ground connections are clean with met-
al-to-metal contact. Use toothed lock washers for
good ground connections.
Z
Be sure that fuses are of the specified rating.
Z
Check the system amperage before applying power
to the wiring.
Z
Check polarity of the battery before connecting pow-
er to the harness.
Z
When it is necessary to remove or partially discon-
nect a wiring harness, label each connector before
removal from its mating instrument.
F28375
Copyright ©