Test 71 - Check Wire 18 Continuity; Test 72 - Test Exercise Function; Test 73 - Test Cranking And Running Circuits - Generac Power Systems CorePower Repair Manual

ENGINE/DC CONTROL
TEST 71 – CHECK WIRE 18 CONTINUITY
Discussion
During cranking and running the controller receives a pulse
from the ignition magneto via Wire 18. If this signal is not
received by the controller the unit will shut down due to no
RPM sensing.
Procedure
1. Set a VOM to measure resistance.
2. Remove Wire 18 from the in-line bullet connector.
Disconnect the J1 Connector from the controller.
3. Verify the continuity of Wire 18. Connect one meter
test lead to Wire 18 removed from the bullet connector.
Connect the other meter test lead to Pin Location J1-4.
CONTINUITY should be measured. If CONTINUITY is not
measured, repair or replace Wire 18 as needed.
Results
Refer to flow chart.
TEST 72 – TEST EXERCISE FUNCTION
Discussion
The following parameters must be met in order for the weekly
exercise to occur:
• AUTO-OFF-MANUAL switch set to AUTO.
Procedure
1. Set the AUTO-OFF-MANUAL switch to MANUAL. The
generator should start. Set AUTO-OFF-MANUAL switch
back to AUTO. Verify that AUTO-OFF-MANUAL switch has
been in AUTO for weekly exercise to function.
2. Hold the Set Exercise switch until the generator starts
(approximately 10 seconds) and then release. All of
the red LEDs will flash for approximately 10 seconds
and then stop. The generator will star t and run for
approximately 12 minutes and then shutdown on it's
own. The exerciser will then be set to start and run at
that time of that day each week. If the unit does not
start, replace the controller.
Results
1. In all models, if the unit star ts in MANUAL, but fails
to exercise without any ALARMS present, replace the
controller.
TEST 73 – TEST CRANKING AND RUNNING
CIRCUITS
Discussion
This test will check all of the circuits that are "Hot" with battery
voltage and which could cause the Main Fuse to blow. Refer
PART 4
to Table 8 throughout the procedure for the known resistance
values of components.
Figure 60 shows the Volt-Ohm-Milliammeter (VOM) in two
different states. The left VOM indicates an OPEN circuit or
INFINITY. The right VOM indicates a dead short or CONTINUITY.
Throughout the troubleshooting, refer back to Figure 60 as
needed to understand what the meter is indicating about the
particular circuit that was tested.
Note: CONTINUITY is equal to .01 ohms of resistance or a
dead short.
Table 8. Components Resistance Values
Starter Contactor
Main Fuel Solenoid
Transfer Relay
Choke Solenoid
OPEN LINE "INFINITY"
OL
Figure 60. Open Line vs. Continuity
Procedure
1. Set a Volt-Ohm-Milliammeter (VOM) to measure
resistance.
2. Disconnect the J1 connector from the controller.
3. Connect one meter lead to a clean frame ground and
connect the other meter test lead to each of the following
tests points in Table 9, measure and record the resistance.
Table 10 has been provided to record the results of this test.
Additional copies of this table can be found in Appendix A
"Supplemental Worksheets" at the back of this manual.
Table 9. Resistance Measurements
Test Point Pin Location
1 J2 Pin 4
2 J2 Pin 11
3 J2 Pin 8
Section 4.5
Diagnostic Tests
8Ω
16Ω
115Ω
4Ω
SHORT "CONTINUITY"
.01
Circuit Value
Wire 14 16Ω
Wire 56 4Ω
Wire 15B OPEN
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