5
Operating Instructions
Alternator field is not energized
Low output voltage with no load
High output voltage with no load
Low output voltage under load
Erratic output voltage
Noisy operation
1. Engine speed is too slow
2. Open, shorted, or incorrect wiring
3. Faulty capacitor
4. Open or shorted field windings
5. Open diodes
1. Engine speed is too slow
2. Open diodes
3. Faulty capacitor
4. Open or shorted field windings
1. Faulty capacitor
2. Engine speed is too fast
1. Open diode
2. Engine speed too slow at full load
3. Excessive load applied
1. Unbalanced engine
2. Dirty, corroded, or loose wiring
connection
3. Unstable load applied
1. Loose generator or engine bolt
2. Short circuit in generator field or
load
3. Faulty bearing
1. Adjust engine speed
✽
2. Referring to the wiring diagram,
clean and reconnect all wiring
✽
3. Replace capacitor
✽
4. Test winding resistance, replace
field winding if necessary
✽
5. Test diodes, replace if necessary
✽
1. Adjust engine speed
✽
2. Test diodes, replace if necessary
✽
3. Replace capacitor
✽
4. Test winding resistance, replace
field winding if necessary
✽
1. Replace capacitor
✽
2. Adjust engine speed
✽
1. Test diodes, replace if necessary
✽
2. Adjust engine speed
✽
3. Reduce the applied load
1. Refer to engine manual
2. Referring to the wiring diagram,
clean and reconnect all wiring
✽
3. Remove all loads, then apply each
one individually to determine which
one is causing erratic function
1. Tighten all mountings
2. Test winding resistance, replace
field winding if necessary
✽
Test load devices for shorts. Replace
defective load device.
3. Replace bearing
✽
These diagnostic and repair procedures should be performed by an authorized service center.
Troubleshooting Chart
Symptom
Possible Cause(s)
Corrective Action
