TM 5-3805-262-20
3-26. SIGNALING DEVICES TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. BACK-UP ALARM DOES NOT SOUND (OTHER CIRCUITS OPERATING OKAY) (Cont) .
S t e p 2 . ( C o n t ).
Connect multimeter between wire lead terminals of back-up alarm
switch .
B e f o r e p e r f o r m i n g t h e f o l l o w i n g , b e s u r e t h a t t r a n s p o r t / s e r v i c e l i n k is
e n g a g e d . F a i l u r e t o d o s o c o u l d c a u s e s e r i o u s i n j u r y o r d e a t h d u e t o
chassis pivoting and crushing you when you are working in area between
front and rear chassis.
Tell assistant to start engine, apply parking brake valve, and place
transmission control lever in R (reverse) position.
Check that multimeter indicates continuity.
a .
b.
If multimeter does not indicate continuity, shut off engine, and
replace back-up alarm switch (page 12-2).
If multimeter indicates continuity, shut off engine, and
reconnect wiring harness wire lead-terminals to–back-up alarm
switch wire lead terminals by grasping with fingers, alining
them, and firmly pushing together. Go to step 3 below.
Step 3. Unlock and open radiator grille.
Connect multimeter between
back-up alarm terminal to which
black-red wire connected and
chassis frame.
T e l l a s s i s t a n t t o s t a r t e n g i n e,
apply parking brake valve, and
place transmission control lever
in R (reverse) position.
Check that multimeter indicates
2 4 v o l t s.
a. If multimeter indicates 24
v o l t s , t e l l a s s i s t a n t t o s h ut
off engine. Connect multimeter
between other back-up alarm
terminal and chassis frame and
check for continuity.
If continuity obtained, replace back-up alarm (page 12-2). If
continuity not obtained, replace wire lead connected to back-up
alarm terminal (page 12-2).
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