Great Plains 3N-3020 Material Rate - Manual (Page 21)

4/28/2004 196-366B
Great Plains Mfg., Inc. 21
8. Keep electrical connects free from dirt and grease.
It is a good idea to occasionally spray the terminals
with contact cleaner to ensure proper connection.
Troubleshooting
Drive will not rotate
1. No power to cab console.
• Check with voltmeter.
• 10 amp fuse on power cable may be blown.
2. ENGAGE button is not on.
• Check to see if green indicator light is on.
• Check to see if hydraulic lever is in detent position.
3. Hydraulic lever is in wrong detent direction.
• A check valve at outlet of motor prevents reverse
rotation.
4. Make sure that both hoses are properly connected
to the tractor remotes.
5. Inadequate system pressure.
• Place pressure gauge at filter and check reading. If
system pressure is below tractor specifications,
check system.
6. Check to see if power and communication cable
(main harness) is properly connected.
• If you see no speed reading when you drive for-
ward, this is not properly connected.
7. No power to external controller.
• Check with voltmeter at connection at control mod-
ule.
8. No signal from radar.
• Check connection external controller, or check ra-
dar.
9. Proportional coil (PN 19799) is defective.
• Check continuity with meter, or energize with 12v
power and check for magnetic pull with small
screwdriver.
10. Excessive torque in drive system.
• Check for a problem with the mechanical portion of
drive, such as foreign material wedged in meter,
frozen bearings or swelled grain in meter.
11. Problem in external controller.
• May require factory service.
Drive Will Not Achieve Desired Rate
1. Check Cal # to ensure that you have entered the
proper cal number for the crop and cup setting.
2. Check to make sure that your desired rate is within
the range on the calibration chart for the row spac-
ing and feeder cup adjustment you have set.
3. Inadequate hydraulic flow.
• Adjust flow control to full open position. Check with
flow meter if flow is suspect.
4. Field speed too high.
• Check maximum planting rate in seed chart for rate
that you should be planting.
Drive Plants Significantly Higher than De-
sired Rate
1. Check Cal # to ensure that you have entered the
proper cal number for the crop and cup setting.
Drive Continues to Rotate After Tractor
Has Stopped
1. Contamination or wear in proportional valve (PN
19798).
• Remove and inspect. Blow out with compressed
air. Check o-rings and re-install. Replace if neces-
sary.
2. Problem in external controller.
• May require factory service.
Fluid Weeping from Motor Shaft Seal
1. Excessive back pressure in return hose.
• Check quick coupler connection. Use motor control
port for return if available.
Motor Appears to Run at Full Speed, Re-
gardless of Setting
1. No speed signal from motor encoder.
• Check connection (No "output" reading should be
on cab console display).
2. Motor speed encoder defective.
• Replace if necessary.
3. Problem in external controller.
• May require factory service.