Guardian 4721, Repair Manual

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Page 57
TEST DESCRIPTION ......................................PAGE
1 Check AUTO-OFF-MANUAL
Switch Position .................................................. 82
2 Try to Start Engine Manually .............................. 82
3 Test AUTO-OFF-MANUAL Switch .................... 82
4 Inspect AUTO-OFF-MANUAL
Switch to control Board Wiring .......................... 83
5 Check 15 Amp Fuse (F1) .................................. 83
6 Check battery .................................................... 83
7 Test Control Contactor CC ................................ 84
8 Test Starter Motor (SM) ...................................... 85
9 Check control Board Power
and Wire 56 Output ............................................ 85
10 Check for Mechanical Damage .......................... 86
11 Check Fuel Supply ............................................ 86
12 Check Wire 14 Output to Distributor .................. 87
13 Benchmark Testing, Distributor
Internal Components .......................................... 88
TEST DESCRIPTION ......................................PAGE
14 Inspect Distributor Cap and Rotor ...................... 88
15 Check Spark Plugs ............................................ 89
16 Check Ignition Wires .......................................... 89
17 Check Ignition Timing ........................................ 89
18 Check DC Volts at Terminal 14 of TB1 .............. 90
19 Test Fuel Solenoid (FS) .................................... 90
20 Check Engine Compression and Condition ........ 90
21 Check Generator Main Line Circuit Breaker ...... 91
22 Check Sensing to control Board ........................ 91
23 Ground control Board Terminal 23 .................... 91
24 Check Voltage at Terminal Lugs E1 & E2 .......... 92
25 Check Voltage at Terminal
Lugs N1 & N2 .................................................... 92
26 Check Voltage at control
Board Terminals N1A and N2 ............................ 92
27 Test Sensing Transformer .................................. 93
PART TITLE PAGE
4.1 Description and Components 58
4.2 Operational Analysis 62
4.3 Troubleshooting Flow Charts 80
Problem 1 - Engine Will Not Crank When
Utility Power Failure Occurs 80
Problem 2 - EngineWill Not CrankWhen AUTO-OFF-
MANUAL Switch is Set to“MANUAL” 80
Problem 3 - Engine Cranks but Won’t Start 81
Problem 4 - Engine Cranks and Starts but
Won’t Transfer to Standby 81
Problem 5 - Engine Starts and Transfer Occurs
When Utility Power is Available 81
4.4 Diagnostic Tests 82
TABLE OF CONTENTS
1.5 LITER PREPACKAGED
HOME STANDBY
GENERATORS
PART 4
DC CONTROL
LIQUID COOLED
ENGINE
UNITS