Service Manual

Key Switch ISB, ISBe and QSB (Common Rail [...]
Page 13-30 Section 13 - Electrical Equipment - Group 13
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Turn the keyswitch to the START position.
The multimeter must indicate system voltage.
If there is no voltage:
• Turn the key switch to the OFF position.
• Check for supply voltage to the keyswitch by
connecting the multimeter positive (+) lead to the key
switch terminal having a wire connecting the keyswitch
to the starter motor solenoid "B" terminal.
Turn the keyswitch to the START position.
If the meter indicates system voltage at the key switch
input terminal, the key switch is defective and must be
replaced. Refer to the original equipment manufacturer's
manual for replacement.
If the meter indicates no voltage, the switch is not the
cause of the complaint.
Check the wiring from the keyswitch to the starter motor
solenoid "B" terminal, and from the starter motor solenoid
to the battery, for broken or damaged wires.