Great Plains 3N-4020 Operator Manual User Manual
Page 97
Great Plains Manufacturing, Inc.
Troubleshooting
93
2013-10-29
196-359M
c.
1 or 10 amp fuse on power cable may be blown.
d.
Engage button is not on - check to see if green
indicator light is on.
e.
Use Cab Console Power Tester (p/n 27857) to
check power out of cab console. Install tester on
round 7-pin power/comm cable from cab con-
sole. Turn drive on. Green LED shows power to
external controller. Red LED shows power to
solenoid. If LED lights are not lit, double-check
power and connections; replace cab console if
needed.
2.
Check communication between cab console and
drive:
a.
Check to see if power and communication cable
(main harness) is properly connected.
b.
If no lower line on cab console appears (speed
and output rate), and drive will not rotate in cali-
bration mode, use Cable Continuity Tester (p/n
27859) to test power and communication to
external controller.
TO PREVENT DAMAGE TO COMPONENTS, DISCONNECT
POWER/COM CABLE FROM CAB CONSOLE AND EXTER-
NAL CONTROLLER BEFORE INSTALLING THIS TESTER.
Install 4-pin test plug on end of 4-pin
power/comm cable before powering the Cable
Continuity Tester - remove before reattaching
power/comm cable directly to cab console.
c.
If Cable Continuity Tester shows power is getting
to external controller, turn power off and remove
Cable Continuity Tester and 4-pin test plug from
ends of power/comm cable. Reattach
power/comm cable to cab console and external
controller.
d.
If power/comm cable tester shows power and
communication is reaching external controller
from cab console, and no lower line appears on
cab console, replace chip or external controller.
Call Service Department.
e.
If Cable Continuity Tester (p/n 27859) isn’t avail-
able, check cable with voltmeter at connection at
control module.
3.
Test Relay inside external controller:
a.
Use Relay Output Tester (p/n 27860) to test relay
inside external controller. Install tester to
weather-pak solenoid connector from external
controller. With tractor engine off, start drive cali-
bration function. Auditory alarm should buzz for
1.5 seconds when drive is engaged in calibration
mode. If no alarm, relay or external controller
may need replacing. Call Service Department.
4.
Check hydraulics:
a.
Check hydraulic lever is in detent position.
b.
Hydraulic lever is in wrong detent direction - a
check valve at outlet of motor prevents reverse
rotation.
c.
Make sure that both hoses are properly con-
nected to tractor remotes.
d.
Inadequate system pressure. Gauge pressure at
filter and check reading. If system pressure is
below tractor specifications, check system.
e.
Power solenoid directly:
Rapid drive rotation may occur causing serious injury.
i.
Disengage hydraulics.
ii.
Reduce flow to 30-50%.
iii. Power solenoid directly by connecting power
weather-pak connector to solenoid
weather-pak connector. If drive doesn’t
rotate, Proportional Coil (p/n 19799) may be
defective. Check continuity with meter, or
energize with 12v power and check for mag-
netic pull with small screwdriver. Dou-
ble-check connections on solenoid cable. If
solenoid energizes but drive does not rotate
when powered directly, tractor hydraulics are
not properly engaged.
f.
Excessive torque in drive system. Disconnect
main drive chain to check for rotation under zero
load. Check for a problem with the mechanical
portion of drive, such as foreign material or
swelled grain wedged in meters, frozen bear-
ings, misaligned chains. Install pressure gauge
at motor inlet. Pressure should be 1000-1500
psi. If pressure is above 2000 psi, significant
torque problems are present.
5.
Check Speed signal (if drive rotates in calibration
mode but not when planting)
Rapid drive rotation may occur causing serious injury.
a.
No signal from speed sensor - check connection
at sensor and at drive controller.