Generac Power Systems 53187 - Manual (Page 137)

PART 5
ENGINE ELECTRICAL SYSTEM
1
Test 12- Check DC Volts at Terminal 1 of
Engine Control Circuit Board (Continued)
PROCEDURE;
1. Set a VOM to read DC volts.
2. Connect the positive {+) VOM test lead to term inal 1
of the engine control circuit board.
3. Connect the com m on (-) test lead to term inal 2 of the
circuit board (ground). The m eter should read battery
voltage.
RESULTS;
1. If battery voltage is indicated, go to Test 6.
2. If battery voltage is NOT indicated, go to Test 9.
Test 13- Check Wiring Between Battery
and Engine Control Circuit Board
DISCUSSION;
If battery voltage is NOT available to the engine
control circuit board on Types 2 and 3 DC control
system s, an open circuit m ust exists som ew ehere be-
tw reen the battery and the circuit board.
PROCEDURE;
Inspect and test w ires betw een the battery and
engine control circuit board. Refer to the appropriate
w iring diagram /electrical schem atic.
RESULTS;
SECTION 5.9
TROUBLESHOOTING TEST PROCEDURES
sary.
Repair, reconnect or replace bad w ire(s) as neces-
Test 15- Test Starter Operation
DISCUSSION;
The follow ing procedure applies only to units w ith
a Type 3 DC control system . Only the Type 3 system
has a starter w ith a pull-in type starter solenoid
m ounted directly to the starter.
PROCEDURE;
See Section 5.2, ENGINE CRANKING SYSTEM.
RESULTS;
Repair or replace defective starter assem bly, as
required.
Test 14- Test Starter Relay
DISCUSSION;
The starter relay (SR) is used only on units w ith a
Type 3 DC control system . The Type 3 unit utilizes a
starter assem bly w hich includes a pull-in type starter
solenoid.
The starter relay is energized w hen engine control
circuit board action delivers DC pow er to the relay, via
W ire 56A. The relay contacts then close to deliver
battery voltage to the starter solenoid, via W ire 56. If
the relay fails, engine cranking w ill not occur.
PROCEDURE;
1. See Figure 4. Disconnect W ire 56A from term inal 86
of the starter relay.
2. Set a VOM to read DC volts. Connect the positive (+)
VOM test lead to term inal 87 of the starter relay; the
com m on (-) test lead to fram e ground.
3. Connect a jum per w ire from relay term inal 30 (W ire
15) to relay term inal 86. The relay should energize. The
VOM connected In Step 2 should read battery voltage.
RESULTS;
1. Replace starter relay if defective.
2. If relay is good, go to Test 15.
Test 16-Check Wire 14 Voltage
DISCUSSION;
During cranking and startup, engine control circuit
board action delivers battery voltage to the W ire 14
circuits. W ires 14 connect to (a) a fuel solenoid, (b) a
fuel pum p, and (c)an hourm eter. W ith the fuel solenoid
and fuel pum p energized, fuel Is delivered to the engine
and the engine can start and run. Circuit board action
w ill keep the W ires 14 circuits electrically hot after
cranking has term inated.
NO TE: On units having a Type 1 DC control system ,
W ire 14 also delivers battery voltage to the actuat­
ing coll of run relay (CR2). the run relay energizes,
Its contacts close, and battery voltage to the engine
control board Is m aintained even after the
start/stop sw itch Is released and cranking has ter­
m inated.
PROCEDURE;
1. Set a VOM to read DC volts.
2. Connect the positive (+) m eter test lead to term inal
9 of the engine control board; the com m on (-) test lead
to term inal 2 (ground).
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