Lull 944E-42 Service Manual - Manual (Page 186)

Electrical System
9-28 944E-42
1. Remove the joystick valve assembly (6) from the
side console. Refer to Section 4.3.6, “Joystick
Assemblies.”
2. Secure the valve body (7) in a bench vise or by other
suitable means.
3. Roll the boot (8) up to expose the locknut at the
bottom of the handle.
4. Lift the wire harness bushing (9) to clear the
retaining hole in the ring on the joystick assembly.
Slide the wire harness out through the slot.
5. Use a vise grip to remove the handle assembly (10)
from the joint assembly (11). Use a punch in the hole
(12) on the joint assembly to hold it in place while
loosening the handle assembly.
6. Remove the handle assembly with the boot. If not
replacing the boot, remove the boot from the handle
assembly.
7. To assemble the new handle, slide the wire harness
through the boot and assemble the boot to the
handle assembly.
8. Roll the boot up to expose the locknut at the bottom
of the handle assembly.
9. Thread the handle assembly onto the joint assembly.
Use a punch in the hole (12) on the joint assembly to
hold it in place while tightening the handle assembly.
10. Assemble the front joystick valve assembly into the
side console. Refer to Section 4.3.6, “Joystick
Assemblies.”
c. Front Joystick Function Solenoid Valve
The front joystick commands are actuated, both
electrically and hydraulically, via a set of solenoid-
operated cartridges within the pilot select valve (13). The
pilot select valve is located on the valve plate which is
located under the cab floor.
d. Solenoid Coil and Cartridge Valve Replacement
If a solenoid coil (14) is suspect of malfunctioning,
disconnect the coil wire lead (15) and test the coil for
proper resistance (8-12 ohms). Replace solenoid if open
or shorted to ground. Also inspect the valve cartridges, o-
rings and other hydraulic and electrical components in
the circuit to accurately determine the cause of the
problem.
The solenoid coils are of the same design. If testing both
coils, insure that the coil wiring connectors are correctly
re-connected.
9.11.10 Optional Single Joystick
This machine can be equipped with an optional single
joystick.
a. Single Joystick Harness Testing
1. Remove the access panel from the side console.
2. Disconnect the single joystick harness connector (1)
from the machine cab harness.
3. Check the cab harness 3 pin connector plug (2) with
a DMM for battery voltage. Place the negative (-)
lead on pin C and the positive (+) lead on pin A, and
test for battery voltage.
If battery voltage is not present, the wiring harness is
suspect and should be replaced. If battery voltage is
present, the harness is functioning properly.
MU4051
4
13
14
15
MU6960
1
3
2
4
5