Manitowoc 999 Service And Maintenance Manual

Reference Only
TROUBLESHOOTING 999 SERVICE/MAINTENANCE MANUAL
10-16
Published 05-16-17, Control # 233-03
Problem 14
Boom will not boom up, but will boom down.
POSSIBLE CAUSES
Maximum bail limit opened; Pump is defective; Boom maximum up limit opened;
Equalizer/boom stop limit opened; Control handle is defective.
CHECKS
Check Diagnostic Screen D2 (see Diagnostic Display topic in section 3).
When applicable switch was enabled…
Bank 1 changed by 2 (front) or 64 (rear) . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum bail limit
Bank 2 changed by 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximum up limit
Bank number increased
by number shown.
Bank number not increased
by number shown.
Does diagnostic DRUM 4 screen (bank 1) approach
+100% handle control with handle moved back?
Check for problem. Repair
limit switch, wiring, or fuse.
Yes No
Yes No
Yes No
Yes
No
Does diagnostic DRUM 4 screen (bank 2) approach
+100% pump control with handle moved back?
Repair or replace control handle.
Use test plug adapter. (See Test 13.) Are -2.3 or more volts
present at pump EDC when control handle is moved back?
Consult dealer/factory.
Can boom pump be manually stroked down? (See Test 16.)
Repair or replace wiring or consult dealer/factory.
Replace pump EDC. Repair or replace pump.
When moving applicable handle fully in both directions, does A1
diagnostic screen (bank 3) 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