Generac Power Systems 16 kW NG User Manual

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Page 134
2.  Disconnect the C3 Connector. 
3.  Set a VOM to measure DC voltage. 
4.  Connect the positive (+) test lead to Wire 56 (Pin 1) of 
C3 Connector going to the control panel (Female Side) 
Connect the negative (-) test lead to Wire 0 (Pin 2).
5.  Set the AUTO-OFF-MANUAL Switch to MANUAL. While 
cranking, battery voltage should be measured. If battery 
voltage  was  not  measured,  verify  continuity  of Wire 
0  between  C3  Connector  and  a  clean  frame  ground. 
Verify continuity of Wire 56 between the C3 Connector 
and Wire 56 connector and J2 Connector Pin Location 
J2-11. Repair or replace any wiring as needed.
6.  Disconnect C3 Connector.
7.  Set a VOM to measure resistance.
8.  Connect the positive (+) test lead to Wire 56 (Pin 1) of 
C3 Connector going to the choke solenoid (Male Side). 
Connect  the  negative  (-)  test  lead  to Wire  0  (Pin  2). 
Approximately 3.7 ohms should be measured.
RESULTS:
1.  If Battery voltage was not measured in Step 5 and wire 
continuity is good, replace the printed circuit board.
2.  If  Choke  Solenoid  coil  resistance  is  not  measured  in 
Step 8, replace the Choke Solenoid.
3.  If battery voltage was not measured in Step 4, replace 
the printed circuit board.
teSt 70 – check For iGnition Spark
DISCUSSION:
If  the  engine  cranks  but  will  not  start,  perhaps  an 
ignition  system  failure  has  occurred.  A  special “spark 
tester” can be used to check for ignition spark.
PROCEDURE:
1.  Remove  spark  plug  leads  from  the  spark  plugs 
(Figure 28).
2.  Attach  the  clamp  of  the  spark  tester  to  the  engine 
cylinder head.
3.  Attach the spark plug lead to the spark tester terminal.
4.  Crank  the  engine  while  observing  the  spark  tester.  If 
spark jumps the tester gap, you may assume the engine 
ignition system is operating satisfactorily.
note: the engine flywheel must rotate at 350 rpm 
(or higher) to obtain a good test of the solid state 
ignition system.
crank cycle sequence table
1=CHOkED
0=OPEN
Note: the first second of each crank cycle is equal to two (2) revolutions of the engine.
Seconds
crank cycle 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
10 kW
0
0
0
0
1
0
0
0
0
1
1
0
0
0
0
0
12 kW-20 kW
0
1
1
0
0
1
1
1
0
0
0
1
1
1
1
1
crank cycle 2
Seconds
10 kW
0
0
0
0
1
0
0
0
0
1
1
0
0
0
0
0
12 kW-20 kW
0
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
crank cycle 3
Seconds
10 kW
0
1
1
1
1
0
0
12 kW-20 kW
0
0
1
1
1
1
1
crank cycle 4
Seconds
10 kW
0
1
0
0
0
0
0
12 kW-20 kW
0
1
0
0
0
0
0
crank cycle 5
Seconds
10 kW
0
1
1
1
1
0
0
12 kW-20 kW
0
1
0
0
0
0
1
 
Part 4
DC CONTROL
sEctioN 4.4
DiaGNostic tEsts