JLG 1230ES Service Manual - Manual (Page 83)

SECTION 5 - CONTROL COMPONENTS
3121222 – JLG Lift – 5-7
To find the source of the difficulty, remove the rear
cover from either drive motor. Insert voltmeter leads
into the white connector leading to the brake sole-
noid (yellow and brown wires) and attempt to drive
(Platform Mode). The Ground Module will apply
approximately 24V to the brake release solenoids
(wired in parallel) during drive, but will reduce this
voltage in the event of a short-circuit. If this voltage
is improper (less than 8V), investigate using resis-
tance measurement (refer to Drive Motor Electrical
Evaluation). Suspect damaged cabling, burned
cabling, or faulty brake release solenoids. Trace the
brake release cabling from the Power Module Com-
partment to the Ground Module Connector J1-24.
11. Open-Circuit Brake Release
This issue will not allow the vehicle to drive. Rapid
motor overheating (both motors) will result. Contin-
ued attempts to drive the vehicle may result in arma-
ture damage.
This situation can be detected by elevating the vehi-
cle's front wheels and engaging drive (platform
stowed). Under DIAGNOSTICS - TRACTION, the
JLG Analyzer's ARM CUR display (Armature Current
Reading) will hover around 350A. The FLD CUR dis-
play (Field Current Reading) will hover around 40A.
It is possible that one wheel may rotate, or neither
may rotate (depending on the location of the open-
circuit). Listen for the brake release solenoid when
activating drive. The Ground Module cannot detect
this fault during power-up or self-test since energiz-
ing the brakes could pose a hazard. However, it may
detect this issue during Drive (investigate using JLG
Analyzer).
If one wheel rotates, the open-circuit is located in the
wiring for that specific drive motor (Power Module
compartment or Drive Motor Cable). Investigate for
improper crimps, unlatched connectors, damaged
cables, or open brake release solenoids (refer to
Drive Motor Electrical Evaluation).
If neither wheel rotates, the open-circuit is located in
the wiring between the Power Module compartment
and Ground Module. Using a voltmeter, measure the
brake release voltage on either brake connector in
the Power Module compartment during drive
(should be approximately 24V). Investigate for
improper crimps, unlatched connectors, damaged
harnessing, or a faulty Ground Module. As an alter-
native, insert a short piece of wire with a Deutsch
Female Crimp directly into Ground Module's J1-24
and measure voltage as a diagnostic measure (eject
vehicle harness from that pin).
5.4 POWER MODULE - P/N-1600346
1 2 3 0 E S S C I S S O R S B U I L T S T A R T I N G I N M I D Y E A R 2 0 1 0
REPLACED THE SEVCON POWER MODULE (P/N-1600473) WITH
THE ZAPI POWER MODULE (P/N-1001092456).
The Sevcon Power Module is located at the front-left side
of the machine inside the compartment as shown in Fig-
ure 5-3. below. Use the following instructions when remov-
ing and installing the power module.
Removal
1. Turn off power machine power and disconnect the
batteries.
NOTE: Note the wire terminal locations when removing the
Power Module (See Figure 5-1.).
2. Disconnect all wires from the power module and
remove the module mounting bolts, remove module
from the machine.
Installation
1. Be sure that the terminals are oriented as shown.
2. After installing the power module, begin connecting
the wires back to the controller. (Reference Figure 5-
1.)
Figure 5-3. Power Module - Installation
1. Power Module 2. Mounting Screws