April 2017
Service and Repair Manual
Boom Components
Part No. 1272854
GTH-844
19
1-1
Boom Proximity Switch
The boom angle switch is a proximity switch. This
switch functions by sensing a change in the
electromagnetic field of the switch, due to the
introduction of metal into the field. A proximity
switch is, simply, a metal detector.
The switch generates an electromagnetic field at
the face of the switch. This field senses when steel
has been moved close to the switch as well as
when the steel has been moved away, which is how
the switch contacts open and close.
These switches are of a fail-safe design. Should the
switch or the switch wire circuit be faulty, the
machine will not function outside its designed range
of use.
The boom proximity switch is a component of the
drive circuit and the chassis sway circuit. Both the
drive and the chassis sway functions are disabled
when the boom is raised to 60° or higher.
How t o T est a Pr oxi mit y Switc h
How to Test a Proximity Switch
1
Remove the switch from the machine. Do not
disconnect the switch wire harness from the
machine.
2
Start the engine.
3
Move the switch away from any ferrous or
metallic object
Result: The light of the limit switch assembly is
not illuminated.
4
Move the switch close to any ferrous or
metallic object
Result: The light of the proximity switch
assembly turns on. The switch is functioning
correctly.
1 boom angle proximity switch (located on
engine side)
Summary of Contents for GTH-844
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Page 61: ...April 2017 Service and Repair Manual Manifolds Part No 1272854 GTH 844 49...
Page 63: ...April 2017 Service and Repair Manual Manifolds Part No 1272854 GTH 844 51...
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Page 67: ...April 2017 Service and Repair Manual Manifolds Part No 1272854 GTH 844 55...
Page 151: ...April 2017 Service and Repair Manual 139 Harness Map Options Work Lights to 15 21456...
Page 155: ...April 2017 Service and Repair Manual 143 Harness Map Options Road Lights to 15 21456...
Page 159: ...April 2017 Service and Repair Manual 147 Harness Map Options Enclosed Cab with Heater...
Page 162: ...Service and Repair Manual April 2017 150 Harness Map Options Enclosed Cab with HVAC...
Page 163: ...April 2017 Service and Repair Manual 151 Electrical Schematic View 1 to 15 20661...
Page 166: ...Service and Repair Manual April 2017 154 Electrical Schematic View 2 to 15 20661...
Page 167: ...April 2017 Service and Repair Manual 155 Electrical Schematic View 1 from 15 20662 to 21456...
Page 170: ...Service and Repair Manual April 2017 158 Electrical Schematic View 2 from 15 20662 to 21456...
Page 171: ...April 2017 Service and Repair Manual 159 Electrical Schematic View 1 from 15 21457 to 21535...
Page 174: ...Service and Repair Manual April 2017 162 Electrical Schematic View 2 from 15 21457 to 21535...
Page 175: ...April 2017 Service and Repair Manual 163 Electrical Schematic View 1 from 15 21536 16E 10000...
Page 178: ...Service and Repair Manual April 2017 166 Electrical Schematic View 2 from 15 21536 16E 10000...
Page 179: ...April 2017 Service and Repair Manual 167 Hydraulic Schematic Single Joystick to 19528...
Page 183: ...April 2017 Service and Repair Manual 171 Hydraulic Schematic Dual Joystick to 19528...