Introduction; Test 14 - Check Fuse; Test 15 - Check Battery & Cables; Test 16 - Check Voltage At Starter - DeWalt DXGN4500 Manual

Introduction

The Diagnostic Tests in this chapter may be performed in
conjunction with the Flow Charts of Section 3.1 and
Section 3.2. Test numbers in this chapter correspond to
numbered tests in the flow charts.
NOTE: Test procedures in this manual are not
necessarily the only methods for diagnosing the condition
of components and circuits. All possible methods that
might be used for system diagnosis have not been
evaluated. If any diagnostic method is used other than
the method presented in this manual, the technician must
be sure that neither his personal safety, nor the product's
safety, will be endangered by the procedure or method
that has been selected.
Test 14 – Check Fuse
General Theory
See Figure 1-1. The fuse protects the wiring and battery
charger from a short circuit.
Procedure
Push in fuse holder cap and turn counterclockwise.
Remove cap with fuse. Inspect fuse.
Results
If fuse element melted open, replace fuse with an
identical size fuse. If fuse is good, refer to flow chart.
Figure 1-1. A Typical Fuse
NOTE: Fuse may be an in-line wire style.
Test 15 – Check Battery & Cables
Procedure
Inspect battery cables and battery posts or terminals for
corrosion or tightness. Measure voltage at the terminal of
Starter Contactor and verify 11-12 VDC is available to
generator during cranking. If voltage is below 11 VDC,
measure at battery terminals during cranking. If battery
voltage is below 11 VDC, recharge/replace battery. If
battery or cables are still suspected, connect an alternate
battery and cables to generator and retest.
Results
Clean battery posts and cables as necessary.
1.
Make sure battery cables are tight.
Diagnostic Repair Manual
Section 3 Engine Diagnostic Tests
Recharge battery if necessary.
2.
Replace battery if necessary.
3.
If battery is good but engine will not crank, refer to
4.
flow charts.
Test 16 – Check Voltage at Starter

Contactor (SC)

Procedure
Set DMM to measure DC voltage.
1.
Disconnect Wire 16 from Starter Contactor located
2.
on Starter motor.
Connect positive meter test lead to Wire 16
3.
previously removed. Connect negative meter test
lead to frame Ground.
Place START-RUN-STOP Switch to START. 12
4.
VDC should be measured.
Reconnect Wire 16 to Starter Motor.
5.
Results
Refer to flow chart.
Test 17 – Check Start-Run-Stop
Switch
General Theory
See Figure 1-2. The START-RUN-STOP switch utilizes
ground potential to start and shutdown the engine. When
the switch is actuated to START, a ground is applied to
the starter contactor where positive 12 VDC is available
allowing the engine to crank. Once ground is removed,
by putting the switch in the RUN, it disengages the starter
allowing the engine to operate normally. When switch is
actuated to STOP, ground is applied to the magneto coils
grounding them out and inhibiting spark from occurring.
Figure 1-2. START-RUN-STOP Switch
Procedure
Set a digital multimeter (DMM) to measure resis-
1.
tance.
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