ENGINE DIVISION SERVICE MANUAL
ELECTRICAL
Fig. 6. Starting Motor Circuit
Excessive resistance in the starting or cranking
system circuit will cause slow cranking speeds and hard
starting. The starting system will function properly only
when the "cranking circuit" and "control circuit" with the
components are in satisfactory condition.
Corrosion, loose terminal, damaged or undersized
cables (wires) will cause cranking problems. In addition,
the switches involved must make good electrical
connections when closed. The voltage drop test will be
performed in three steps: cranking circuit, control circuit
and grounded side.
Cranking Circuit: Voltage drops are measured by
connecting a voltmeter in parallel across the circuit or
section of a circuit being inspected, then reading the
voltmeter while circuit is in operation. To test voltage
drop in the cranking circuit from battery to starter,
connect the voltmeter (observing the polarity and voltage
rating of meter) to battery post (not clamp) to starter
motor terminal as shown in Fig. 7. Prevent engine from
starting during test. Crank engine and observe voltmeter
reading.
CGES-230 - Page 7
PRINTED IN UNITED STATES OF AMERICA
