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