Generac Power Systems 941-2 Service Manual page 120

Section 7.2
ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING
TEST 1- CHECK 7.5 AMP FUSE
DISCUSSION:
The panel-mounted 7.5 amp fuse is connected in
series with the 12 VDC power supply to the engine
DC control system. A blown fuse will prevent engine
priming, cranking and running.
TEST PROCEDURE:
Push in on fuse holder cap and turn it counterclock-
wise to remove cap and fuse. Check the fuse visually.
If the fuse metal element has melted open, replace
the fuse.
If the visual check is uncertain, use a VOM to check
fuse.
RESULTS:
1. If fuse is good
a. And if priming function does not work, go to
Test 2.
b. And if engine will not crank, go to Step 4. 2. If
fuse is bad, replace it.
Figure 1. 7.5 Amp Fuse
TEST 2- CHECK POWER TO PRIMER SWITCH
DISCUSSION:
This is a check of the PRIMER SWITCH on the panel.
When the switch is actuated to its "PRIME" position,
fused battery voltage is delivered directly to the elec-
tric fuel pump on units with gasoline fuel system. On
units with gaseous fuel system, battery voltage is
delivered to the fuel lockoff solenoid.
TEST PROCEDURE:
Set a VOM to read battery voltage (12 VDC). Connect
the meter test leads across the Wire 15 terminal of
the Primer Switch and frame ground. The meter
should read battery voltage.
RESULTS:
1. If battery voltage is indicated, go to Test 3.
2. If battery voltage is NOT indicated, go to Test 4.
Page 7.2-10
Figure 2. Primer Switch
TEST 3- CHECK POWER TO FUEL PUMP
DISCUSSION:
When the rocker type primer switch is held at ON",
position, fused battery voltage is delivered to the elec-
tric fuel pump. The pump should then turn on and
prime the carburetor.
During cranking and startup, the A6060 circuit board
will deliver battery voltage to the Wire 14 circuit and
to the Fuel Pump. The pump should turn on and run.
Figure 3. Fuel Pump
TEST PROCEDURE:
Locate the red Wire 14A that connects to the fuel
pump. A wiring connector connects the wires near the
pump. Separate the wire, then check for DC power as
follows:
1. Set VOM to read battery voltage.
2. Connect the VOM test leads across the Wire 14A from the
Primer Switch and frame ground.
3. Hold the Primer Switch at °ON" (Prime). Meter should read bat-
tery voltage.
4. Hold the panel Start-Run-Stop switch at "START". The meter
should read battery voltage.