
Section 5 — Troubleshooting
Guardian 
5.1TROUBLESHOOTING GUIDE
PROBLEM | CAUSE | CORRECTION | ||
The engine will not crank.  | 1.  | Fuse blown  | 1.  | Replace fuse.  | 
  | 2.  | Loose, corroded or defective  | 2.  | Tighten, clean or replace  | 
  | 
  | battery cables  | 
  | as necessary.  | 
  | 3.  | Defective starter contactor  | 3.  | *  | 
  | 4.  | Defective starter motor  | 4.  | *  | 
  | 5.  | Dead Battery  | 5.  | Charge or replace battery.  | 
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The engine cranks but  | 1.  | Out of fuel  | 1.  | Replenish fuel.  | 
will not start.  | 2.  | Defective fuel solenoid (FS)  | 2.  | *  | 
  | 3.  | Open #14 wire from  | 3.  | *  | 
  | 
  | engine control board  | 
  | 
  | 
  | 4.  | Defective spark plug(s)  | 4.  | Clean,   | 
  | 5.  | Dirty/Blocked air filter  | 5.  | Clean or replace as required.  | 
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The engine starts hard  | 1.  | Air cleaner  | 1.  | Check, clean or replace air cleaner.  | 
and runs rough.  | 
  | plugged or damaged  | 
  | 
  | 
  | 2.  | Defective spark plug(s)  | 2.  | Clean,   | 
  | 3.  | Dirty/Blocked air filter  | 3.  | Clean or replace as required.  | 
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The engine starts, but then  | 1.  | Engine oil level low  | 1.  | Check oil and add oil as needed.  | 
shuts down.  | 2.  | Defective low oil  | 2.  | *  | 
  | 
  | pressure switch  | 
  | 
  | 
  | 3.  | Defective high temperature  | 3.  | *  | 
  | 
  | switch  | 
  | 
  | 
  | 4.  | Defective control board  | 4.  | *  | 
  | 5.  | Low coolant level  | 5.  | Check coolant level, repair leaks  | 
  | 
  | 
  | 
  | and refill.  | 
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The Auto/Off/Manual switch  | 1.  | Defective switch  | 1.  | *  | 
is set to OFF, but the engine  | 2.  | Defective control board  | 2.  | *  | 
continues to run.  | 
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There is no AC output from  | 1.  | Generator main line circuit  | 1.  | Reset circuit breaker  | 
the generator.  | 
  | breaker open  | 
  | to ON (or closed).  | 
  | 2.  | Generator internal failure  | 2.  | *  | 
  | 
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There is no transfer to  | 1.  | Generator main line circuit  | 1.  | Reset circuit breaker  | 
standby after utility  | 
  | breaker open  | 
  | to ON (or closed).  | 
source failure.  | 2.  | Defective transfer switch coil  | 2.  | *  | 
  | 3.  | Defective transfer relay  | 3.  | *  | 
  | 4.  | Transfer relay circuit open  | 4.  | *  | 
  | 5.  | Defective control logic board  | 5.  | *  | 
*Contact your nearest Generac/Guardian Authorized Dealer for assistance.
20 Generac® Power Systems, Inc.