Manitowoc 999 Service And Maintenance Manual

Reference Only
TROUBLESHOOTING 999 SERVICE/MAINTENANCE MANUAL
10-12
Published 05-16-17, Control # 233-03
Problem 10
Front or rear load drum will not lower load, but will raise load.
POSSIBLE CAUSES
Pawl in; Control handle is defective; Minimum bail limit opened;
Pump is defective; Speed sender is defective.
CHECKS
Check Diagnostic Screen D2 (see Diagnostic Display topic in section 3).
When applicable switch was enabled…
Bank 1 changed by 4 (front) or 128 (rear). . . . . . . . . . . . . . . . . . . . . . . . . Minimum bail limit
Bank number increased
by number shown.
Bank number not increased
by number shown.
Does diagnostic DRUM 1 or 2 screen (bank 1) approach
-100% handle control with handle moved forward?
Check for problem.
Repair limit switch,
wiring, or fuse.
Repair or replace control handle.
Does diagnostic DRUM 1or 2 screen (bank 2)
approach -100% pump control with handle
moved forward?
Consult dealer/factory.
Use test plug adapter. (See Test 11.) Are 12 volts present at
brake solenoid valve when control handle is moved?
(See Test 13.) Repair or replace wiring or consult dealer/factory.
Yes No
Yes
No
Yes No
When moving problem handle fully in both directions,
does A1 diagnostic screen (bank 1 and 2) read 38 to
120 in lower or 136 to 215 in raise?
Yes
No
Repair or replace control handle/wiring.

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English