20 Generac
®
Power Systems, Inc.
Section 5 — Troubleshooting
Guardian Liquid-cooled 40 kW Generator
5.1 TROUBLESHOOTING
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.
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, re-gap or replace plug(s).
5. Dirty/Blocked air filter
5. Clean or replace as required.
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, re-gap or replace plug(s).
3. Dirty/Blocked air filter
3. Clean or replace as required.
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.
The Auto/Off/Manual switch
1. Defective switch
1. *
is set to OFF, but the engine
2. Defective control board
2. *
continues to run.
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. *
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.
