Test 27 - Check Start-Run-Stop Switch (Sw1); Test 28 - Check Start-Run-Stop Switch (Sw1) Wiring; Test 29 - Check Ignition Spark - Generac Power Systems GP Series Diagnostic And Repair Manual

Section 4 AC Diagnostic Tests
Results
If Continuity was not measured in step 13 replace the
starter contactor relay. If all steps passed refer back to
flow chart.
Test 27 – Check Start-Run-Stop
Switch (SW1)
Procedure
Set DMM to measure resistance.
1.
Remove all wires from the start-run-stop switch
2.
(SW1).
Use the chart below to check the condition of the
3.
start-run-stop switch.
Connect one meter test lead to one terminal and
4.
the other meter test lead to the other terminal.
With meter leads connected activate the switch to
5.
START, STOP or RUN and follow the chart.
Connect all wires to the switch.
6.
CONDITION TERMINALS
STOP
STOP
STOP
STOP
RUN ALL CONDITIONS
START
START
START
START
Figure 4-35. Start-Run-Stop Switch (SW1)
Results
If the switch fails any part of the test procedure replace
the switch.
50
RESULT
5,4 OPEN
5,6 CLOSED
2,1 OPEN
2,3 CLOSED
OPEN
5,4 CLOSED
5,6 OPEN
2,1 CLOSED
2,3 OPEN
0
STOP 0
6 3
5 2
RUN
167
4 1
START 15
17
15
Test 28 – Check Start-Run-Stop
Switch (SW1) Wiring
Procedure
Set DMM to measure resistance.
1.
Remove wire 17 from the starter contactor relay
2.
(SCR).
Connect one meter test lead to wire 17.
3.
Remove wire 17 from the start-run-stop switch
4.
(SW1).
Connect the other meter test lead to wire 17.
5.
a. Continuity should be measured.
See Figure
6.
positions on the start-run-stop switch (SW1).
Connect a meter test lead to each wire 0.
7.
a. Continuity should be measured.
Connect one meter test lead to one wire 0 and
8.
connect the other meter test lead to frame ground.
a. Continuity should be measured.
Set DMM to measure DC voltage.
9.
Remove wire 15 from the start-run-stop switch
10.
(SW1).
Connect the positive meter test lead to wire 15.
11.
Connect the negative meter test lead to frame
12.
ground.
a. 12 VDC should be measured.
Results
Repair or replace any wiring that did not have continuity.
If voltage was not measured in step 12 repair wiring
between the starter contactor relay (SCR) and the start-
run-stop switch (SW1).
If all steps passed, repair or replace wire 16 between the
starter contactor (SC) and the starter contactor relay
(SCR).
Test 29 – Check Ignition Spark
Procedure
A commercially available spark tester may be used to
test the engine ignition system. One can also be
purchased from Generac Power Systems (Part No.
0C5969).
004653
Disconnect a high tension lead from a spark plug.
1.
Attach the high tension lead to the spark tester
2.
terminal.
See Figure
3.
attaching to the cylinder head.
4-35. Remove wire 0 from both
4-36. Ground the spark tester clamp by
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