Lull 944E-42 Service Manual - Manual (Page 529)

9.19 Model 644E-42/944E-42 Rev. 6/04
Electrical System
9.4 EFFECTIVE GROUND CONNECTIONS
1. Effective ground connections are essential to the
efficient operation of electrical components. If an
inadequate ground is suspected or determined,
establishing another ground may be desired. Also, in
the event a factory-authorized accessory is being
installed, it is necessary to follow the proper
sequence for providing an electrical ground. The
sequence for installing or attaching a component to
an electrical ground to a stud, bolt or capscrew (1) is
to provide a clean surface by eliminating paint and
rust from the area around the base of the stud (2).
Install a tooth type lockwasher (3), electrical wire
connector (4), flat washer (5), tooth or slot-type
lockwasher (6) and nut or locknut (7). Torque
hardware as specified in instructions.
2. When an electrical component (8) is to be grounded,
eliminate paint and rust from around the stud, bolt or
capscrew (9), install a flat washer (10), tooth type or
slot-type lockwasher, or locking nut with slotted type
lockwasher (11) and nut or locknut (12). Torque
hardware as specified in instructions.
9.5 GROUNDING STRAPS
There are four grounding straps located throughout the
vehicle. Before troubleshooting the electrical circuits,
make sure that all of the ground straps are intact and
securely fastened to the vehicle.
For locations of the grounding straps refer to Section
9.1.12, “General Overview (Vehicle Ground Strap
Locations).”
9.6 WIRING HARNESSES
Wiring on the standard 644E-42 vehicle is contained
within five separate wiring harnesses; the open cab
harness, vehicle power harness, vehicle transmission
harness, vehicle sensors harness and vehicle control
harness.
Wiring on the standard 944E-42 vehicle is contained
within six separate wiring harnesses; the open cab
harness, ECM cab harness, ECM vehicle power harness,
vehicle transmission harness, vehicle sensors harness
and vehicle control harness.
Note: Some early production units have a separate wire
harness running between the auxiliary hydraulic
pressure release switch and valve. Later production units
have this harness incorporated into the open cab
harness
A harness consists of black-nylon woven braiding,
providing a protective cover to bundle numerous wiring
groups, splices, terminals, connectors, and, where
applicable, diodes. Each harness is identified with a JLG
part number when the vehicle leaves the factory.
Each wire is identified by a wire number on each end of
the individual wire, and by the color and gauge size of the
wire. The wire numbers are also identified on the
appropriate electrical schematic. All circuits have been
electrically tested for continuity, and all diodes have been
tested for correct biasing. Where several individual
connectors appear, the wiring leading to a particular
connector can help identify the specific circuit. For some
circuits, a colored band (tie wrap) is present, affixed to the
connector wiring and used as a color-code indicator. If
wiring ever needs to be replaced, use the correct gauge
size wiring. NEVER replace a wire with a smaller gauge
wire.
MA0871
1
2
3
4
5
6
7
MA0881
8
9
10
11
12