CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
ENGINE MANIFOLD PREHEATER SYSTEM-Continued
WARNING
Remove all jewelry such as rings, dog tags,
bracelets, etc. If jewelry contacts a metal
surface a direct short may result in instant
heating of tools, damage to equipment, and
injury or death to personnel.
C Reconnect wire 486 to Y-connector on manifold preheat
switch side. Disconnect wire 486 from switch panel side
of 15 A circuit breaker. Place red lead of multimeter on
female connector of wire 486 and black lead to ground.
Turn MASTER switch on, push START switch, and check
for voltage. Turn MASTER switch OFF. If voltage is
present, go to step D. If voltage is not present,
repair/replace wire 486 or air cleaner circuit breaker lead
assembly (see paragraph 6-82).
D Reconnect wire 486 to switch panel side of 15 A circuit
breaker. Disconnect wire 486 from manifold preheater
switch side of 15 A circuit breaker. Place red lead of
multimeter on circuit breaker terminal and black lead to
ground. Turn MASTER switch on, push START switch,
and check for voltage. Turn MASTER switch OFF. If
voltage is present, go to step E. If voltage is not present,
replace 15 A circuit breaker.
E Reconnect wire 486 to manifold preheater switch side of
15 A circuit breaker. Disconnect wire 486 from circuit
breaker side of manifold preheater switch. Place red
lead of multimeter in wire 486 and black lead to ground.
Turn MASTER switch on, push START switch, and check
for voltage. Turn MASTER switch OFF. If voltage is
present, go to step F. If voltage is not present,
repair/replace wire 486 of switch panel to neutral safety
to bulkhead wiring harness from circuit breaker to
manifold preheat switch assembly (see paragraph 6-54).
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