Section 5 - Troubleshooting; Troubleshooting Points - Generac Power Systems 004721-0, 004722-0, 004723-0, 004724-0, 004725-0, 004725-1, 004725-2, 004725-3, 004726-0 Owner's Manual

5.1

TROUBLESHOOTING POINTS

PROBLEM
Engine won't crank.
Engine cranks but won't start
Engine starts hard, runs rough.
Engine starts then shuts down.
AUTO/OFF/MANUAL Switch at OFF,
engine continues to run
No AC output from generator.
22 Generac ® Power Systems, Inc.
Section 5 — Troubleshooting
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
CAUSE
1. 15 amp fuse blown.
2. Loose or corroded or defective
battery cables.
3. Defective starter contactor.
4. Defective starter motor.
5. Dead or Defective Battery.
1. Out of fuel.
2. Fuel solenoid (FS) is defective
3. Open Wire #14 from Engine Control
circuit board.
4. Spark plugs defective.
1. Flame arrestor (air cleaner) plugged or
damaged.
2. Plugged fuel line.
3. Defective spark plugs.
1. Engine oil level is low.
2. Engine is overheated.
3. Defective Low Oil Pressure Switch
4. Defective Coolant Temperature Switch
5. Defective Control Module circuit board.
6. Coolant Level is Low.
7. Defective Low Coolant Level Switch
1. Defective AUTO/OFF/MANUAL switch
2. Open/disconnected wire #15A between
AUTO/OFF/MANUAL switch and Control
Module circuit board.
3. Defective Control Module circuit board
1. Check main line circuit breaker.
2. Check circuit breaker & fuses.
3. Transfer switch set to NORMAL position
4. Generator internal failure.
5. Thermal circuit breaker open.
CORRECTION
1. Replace fuse.
2. Tighten, clean or replace
battery cables as necessary.
3. Replace contactor.
4. Replace starter motor.
5. Remove, change or replace battery.
1. Replenish fuel.
2. Replace solenoid.
3. Reconnect wire.
4. Clean, regap or replace plugs.
1. Clean or replace as needed.
2. Unclog fuel line.
3. Clean, regap or replace plugs.
1. Check oil and add oil as needed.
2. Check cooling system for leaks.
3. Replace switch.
4. Replace switch.
5. Replace board.
6. Repair leak - Add coolant.
7. Replace Switch.
1. Replace switch.
2. Reconnect/close wire.
3. Replace board.
1. Reset to ON or CLOSED.
2. Reset and replace, if necessary.
3. Set to GENERATOR position.
4. Contact an Authorized Generac
facility.
5. Auto-reset - Wait five min. and
attempt restart.