Guardian Technologies 4758 - Manual (Page 108)

SECTION 4.4
DIAGNOSTIC TESTS
DC CONTROL
4. If the engine cranks but does not start and battery
voltage was measured in Steps 2, 3 and 4, and
CONTINUITY was NOT measured in Step 6, repair or
replace Wire 0 between the Control Panel ground
connection and the Fuel Solenoid terminal. If
CONTINUITY was measured in Step 6, proceed to Test
52 or test 54 depending on the model.
TEST 54 - CHECK FUEL SOLENOID
DISCUSSION:
In Test 53, if battery voltage was delivered to Wire 14,
the fuel solenoid should have energized open. This test
will verify whether or not the fuel solenoid is operating.
Fuel Solenoid Nominal Resistance 27-3 33 ohms.
Figure 18. The Fuel Solenoid (FS)
PROCEDURE:
1. Disconnect Wire 56 from the starter contactor relay
(SCR). This will disable the unit from cranking. For
single cylinder units, disconnect from the starter
contactor (SC) and isolate it from ground.
2. Place one hand on the Fuel Solenoid (FS). Cycle the
AUTO-OFF-MANUAL switch from MANUAL to OFF.
You should be able to feel the solenoid actuate as well
as hear it actuate. If a small screwdriver is placed on the
solenoid and then gently pulled away, a magnetic field
should be felt.
3. Set the AUTO-OFF-MANUAL switch to OFF. Reconnect
Wire 56 to starter contactor relay or starter contactor.
RESULTS:
1. If solenoid actuates, go to Test 55.
2. Replace the solenoid if it does not actuate.
TEST 55 - CHECK FOR IGNITION SPARK
DISCUSSION:
If the engine cranks but will not start, perhaps an
ignition system failure has occurred. A special "spark
tester" (Generac P/N 0C5969) can be used to check
for ignition spark.
Figure 19. Spark Tester
PROCEDURE:
1. Remove spark plug leads from the spark plugs
(Figure 20).
2. Attach the clamp of the spark tester to the engine
cylinder head.
Figure 20. Checking Ignition Spark
PART 4
Page 4.4-11