Generac Power Systems IM Series - Manual (Page 21)

Step 4 - Test Automatic Choke
Test Procedure: Refer to Steps 7 and 8 of Problem No.
2 for automatic choke system test procedures. See AD­
JUSTMENTS section as well.
Test Results:
A. Choke tests GOOD; Repeat Steps 1 thru 3.
B. Choke tests BAD: Repair, adjust or replace defective
component(s) as necessary.
Problem No. 5 - Engine Won’t Shut Down
Step 1 - Check Start/Stop Switch.
Test Procedure: Test the Start/Stop Switch (Fig. 13) as
follows;
1. Check Wire 0 (between Start/Stop Switch and ground
terminai QT) for open condition. Ground connection
must be good before proceeding.
2. Disconnect Wires 17 and 18 from Switch terminals, to
prevent interaction.
3. Set VOM "Rxl" scale and zero the meter.
4. Connect one meter probe to the Wire 17 terminal, and
connect the remaining test probe to Wire 0 (ground)
terminal. Meter should indicate infinity.
5. Actuate the Switch to its START position. Meter
should read continutity.
6. Release Switch. Meter should indicate infinity.
7. Set Switch to STOP. Meter should indicate infinity.
8. Connect one meter probe to the Wire 18 terminal of
Switch, and connect the remaining test probe to Wire 0
(ground) terminal. With Switch at START, VOM should
indicate infinity. Hold Switch at STOP and meter should
read continuity.
Test Results:
A. Start/Stop Switch SW1 checks GOOD: Go to Step 2.
Step 2 - Check Wire 18
Test Procedure: Refer to WIRING DIAGRAM, Page 11.
Test Wire 18 between Ignition Shutdown Module ISD and
Start/Stop Switch for open or shorted condition. Also
check Wire 18 between Start/Stop Switch and Control
Relay CR2 for open or shorted condition.
Test Results:
A. Wire 18 checks GOOD: Go to Step 3.
B. Wire 18 checks BAD: Repair or replace.
Step 3 • Check Engine Ignition System
Test Procedure: See ENGINE TROUBLESHOOTING
section in this Manual. Also see ENGINE SERVICE
MANUAL.
Test Results:
Repair or replace defective ignition components as
necessary.
Problem No. 6 - Loss of Generator a-c
Output
step 1 - Check Circuit Breakers CB1/CB2
Test Procedure: Try resetting applicable circuit breaker.
If this does not correct the problem, use a VOM to test
the circuit breakers.
Test Results:
A. Problem is corrected by resetting Breaker: STOP test.
B. Circuit Breaker tests GOOD, still little or no a-c output:
Go to Step 2.
C. Circuit Breaker tests BAD: Replace Circuit
Breaker(s).
Step 2 - Check Vehicle Wiring
Test Procedure: Check vehicle a-c wiring and a-c dis­
tribution components.
Test Results:
A. Vehicle wiling checks GOOD: Go to Step 3
B. Vehicle wiring checks BAD; Repair or replace as
needed.
Step 3 - Check a-c Voltage and Frequency
Test Procedures: Check generator a-c output voltage
frequency (Fig. 14) as follows:
1. Disconnect generator a-c output leads T1 (red), T2
(white) and T3 (black) in the junction box where they
connect to vehicle wiring.
2. Connect an accurate a-c voltmeter and frequency
meter across generator a-c output leads T1 (red) and T2
(white).
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