Lull 944E-42 Service Manual - Manual (Page 686)

Electrical System
9.176 Model 644E-42/944E-42 Rev. 6/04
9.13 ELECTRICAL SYSTEM
COMPONENTS
Electrical components include warning devices such as
the indicators in the front dash panel, horn, back-up
alarm, and other components such as the joystick,
various solenoids and all accessories.
Examine the appropriate wiring diagrams and schematics
earlier in this section to help understand the wiring
circuits involved.
9.13.1 Warning Devices
Vehicle warning devices include the horn, dash panel
warning lights, and the back-up alarm.
a. Horn
The horn with bracket (1) is mounted on the inside of the
left frame rail (2) near the front right corner of the cab
support (3).
The horn sounds when the momentary-contact horn
button on the center of the steering wheel is pressed.
Removal of the horn button is discussed in Section 4.3.2,
“Steering Wheel, Transmission Travel and Gear Select
Lever and Turn Signal Select Lever,” of this manual.
The horn sound is produced by a solenoid-actuated
diaphragm in the horn that develops a resonating air
column in the horn trumpet, which is shaped to project the
sound. If the horn doesn’t sound when the horn button is
pressed, check that the fuse is not blown.
Check for corrosion on the horn mounting that may be
preventing a solid ground, and check for a loose horn
wire. Test the horn switch for continuity when the horn
button is pressed.
If the problem is still not located, remove the horn from
the frame.
Horn Removal
1. Unlock and open the engine cover (7).
2. If the vehicle has dual batteries, disconnect both
negative battery cables (9 and 10) from both
batteries.
To access the lower battery (11), loosen the knob
(12) far enough so that the lip (13) on the upper
battery box clears the knob. Lift up the upper battery
box (14) and swing it out, so that the box clears the
hydraulic tank support bracket, to gain access to the
lower negative battery cable (9). Disconnect the
lower negative battery cable.
MU3230
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4110390
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OU0780
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