ELECTRICAL SYSTEMS TROUBLESHOOTING (CONT)
PROBLEM NO. 1
(Sheet 1 of 6)
WILL NOT CRANK
Batteries fully charged. See page 2-269.
Cables good and installed correctly. See page 2-279.
Connectors clean and tight on posts.
Gages, lights, etc. work with POWER switch in ON position (see NOTE A).
NOTE A: If gages, lights, etc. do not work, see PROBLEM 6.
TROUBLESHOOT STARTING CIRCUIT
For battery power to turn the starting motor in this system, five switches must be closed.
Three of these are magnetic switches that are electrically activated:
A. Starter solenoid located on the starting motor.
B. Starter relay located on the engine relay panel. See page 2-60.
C. Start interlock relay located on the engine relay panel. See page 2-60.
The other two are manually activated switches:
D. Main disconnect located near engine relay panel.
E. POWER key switch at START position located on right-hand instrument panel.
The main disconnect switch (D) should always be closed except when working on the starting system components. The POWER switch (E) connects battery power to the
starting circuit to energize the coil on the starter relay (B). However, the coil can only be energized if the current can flow to ground. The start interlock relay (C) provides
the ground path as long as it is closed. (NOTE: This relay is normally closed and opens when the alternator starts up. This prevents the starter relay from closing if the
power switch is accidentally turned to START while the engine is running.) When the coil on the starter relay (B) is energized, power goes from the battery to the start
solenoid (A), which closes the circuit to the starting motor.
Go on to Sheet 2