Lull 944E-42 Service Manual - Manual (Page 609)

9.99 Model 644E-42/944E-42 Rev. 6/04
Electrical System
Before troubleshooting any
electrical circuit, ALWAYS
begin by checking the
following:
1. All connections relating to
circuit are clean and tight.
2. All grounding straps are
intact and securely
fastened, refer to Section
9.1.12, “General Overview
(Vehicle Ground Strap
Locations).”
If
OK
Not OK
Not
OK
Replace failed solenoid.
Repair/replace
single joystick
harness.
Replace single
joystick relay.
Not
OK
Plug cab harness back into
single joystick harness,
measure battery voltage
across solenoid HO,
connector wires [LEA] (GRN)
and [SJG4] (BLK).
Not OK If OK
Problem is hydraulic. Refer to
Section 8, “Hydraulic
System,” pages 8.76 or 8.80
Check power at wire
[AH1C] (RED/WHT) at single
joystick relay.
If OK
Reconnect harness. Verify
that solenoid is magnetized
by holding a metal object next
to the solenoid. Or, test
resistance in solenoid. Refer
to page 9.233
If OK
Unplug single joystick
harness at hyd joystick
connector and measure
battery voltage at pin A.
Wire [AH1] (RED/WHT) is
open. Repair/replace open
cab harness.
Replace fuse.
Check auxiliary hydraulic
(F10) 5 amp fuse.
Not
OK
Not
OK
If OK
If OK
Not
OK
Verify wire [AHG6] (BLK)
ground connection at cab
ground stud.
Repair/secure ground
connection properly.
If OK
Not
OK
At hyd joystick connector,
verify ground connection at
pin C, wire [AHG6] (BLK).
Repair/replace open cab
harness.
If OK
Verify battery
voltage at wire
[LE] (GRN) on
single joystick relay.
Repair/replace
single joystick
harness.
Boom fails to lift or lower.
Single Joystick
Pilot Select Valve Solenoids
Function
Abbreviation
on Valve
Transfer Carriage TR
Auxiliary Hydraulics AX
Extend/Retract EXT
Lift/Lower HO
Attachment Tilt Down CTB
Attachment Tilt Up CTA