Bank Number Not Increased
by Number Shown
PROBLEM 16
Boom will not boom down, but will boom up.
POSSIBLE CAUSES
Boom maximum down limit opened. Minimum bail limit open. Pawl engaged. Pump is worn.
Block-up limit open. Control handle is worn. RCL circuit open. Speed sender is bad.
CHECKS
Check Diagnostic Screen D2. (See Diagnostic Display topic in this section of manual.)
When applicable switch was enabled…
Bank 1 changed by 4 (front), 8 (left rear), or 128 (right rear) . . . . . . . . . . Maximum bail limit
Bank 2 changed by 32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum up limit
Bank 6 changed by 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RCL
Bank Number Increased
by Number Shown
Yes No
Out In
Yes No
Yes No
Yes
No
Yes
No
Does diagnostic screen D2 (bank 2, boom pawl command)
change by 16 when moving brake park switch?
Check for problem. Repair
limit switch, wiring, or fuse.
Visually check pawl.
(See Problem 29.)
Repair or replace switch or wiring to PC.
Does diagnostic DRUM 4 screen (bank 1) approach 100% handle control with handle moved forward?
Does diagnostic DRUM 4 screen (bank 2) approach 100% pump
control with handle moved forward?
Repair or replace
control handle.
Use test plug adapter. (See Test 4—Testing the Pump EDC and
Motor PCP.) Are +2.3 or more volts present at pump EDC when
control handle is moved forward?
Consult the Manitowoc
Crane Care Lattice Team.
Repair or replace wiring or consult the Manitowoc Crane Care Lattice Team.
Replace pump EDC.
Repair or replace pump.
Can boom pump be manually stroked down? (See Test 10—
Manually Stroking the Pump.)
To Next Page
Loading...
Need help?
General
