TM 5-3805-280-24-1
Sub-System Diagnostics
ACCESSORY CIRCUITS OPERATIONAL INFORMATION
In order for the circuits to function, the key switch must
be in the ACC or ON position.
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ACCESSORY CIRCUITS THEORY OF OPERATION
9015
Power from dome light 5-amp fuse F18 is applied to
The accessory circuits include the horns (B25, B26),
15
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dome light switch S3. When the switch is turned ON,
the cab dome light (E3), and the 24-volt power plug
power is applied to cab dome light E3, turning the light
(G4).
on.
Power from horn 10-amp fuse F15 is applied to
Power from lighter 10-amp fuse F17 is applied to
terminal 1 and 3 of horn relay K5. When horn switch
24-volt power plug G4.
S2 is pressed, the closed contacts of the switch apply
ground to terminal 2 of the horn relay, and the relay is
energized. With the relay is energized, power is
applied from relay terminal 5 to high and low note
horns B25 and B26, sounding the horns.
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