TM-9-2320-272-23-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-1 - Page 960 of 1313
HEATER WILL NOT OPERATE WITH SWITCH IN LOW POSITION (HIGH POSITION OPERATION NORMAL) -
Continued
STEP
4.
IS THERE BATTERY VOLTAGE AT BATTERY SWITCH TERMINAL?
a.
Place battery switch to OFF position.
T0128DAA
569A
Figure 4.
Battery Switch Wire 569A.
b.
Disconnect circuit 569A wire to circuit breaker from battery switch.
c.
Place battery switch to ON position.
d.
Connect multimeter red lead to the open circuit 569A wire contact (D) on battery switch. Refer to point
to point schematics.
e.
Connect multimeter black lead to vehicle chassis ground.
f.
Meter reading should be 12 VDC or greater.
CONDITION/INDICATION
IS THERE BATTERY VOLTAGE AT BATTERY SWITCH TERMINAL?
DECISION
NO - Replace defective battery switch (Volume 2, WP
0307). Go to Step (5) to verify problem is solved.
YES - Repair or replace circuit 569A wire from battery switch to circuit breaker (Volume 3, WP
0352). Go to
Step (5) to verify problem is solved.
TM 9-2320-272-23-1
0114
0114-5
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