Engine Troubleshooting - Universal M3-20A Operator's Manual

ENGINE TROUBLESHOOTING
The following trouble shooting chart describes certain prob-
lems, the probable causes of the problems, and the recom-
mendations to overcome the problems.
Problem Probable Cause
Key switch on, PREHEAT switch 1. Battery Switch not on.
depressed: no panel indications:
fuel solenoid or electrical fuel pump 2.
20-Amp circuit breaker tripped.
J. 10-Amp breaker tripped.
4. Loose battery connections.
5. Preheat solenoid not operating.
Key switch on, PREHEAT switch 1. Connection to solenoid faulty.
depressed: START switch depressed;
no starter engagement. 2. Faulty START switch.
J. Faulty solenoid.
4. loose battery connections.
5. Low batteries.
Engine cranks, but does not 1. Faulty fueling system.
start.
2. Preheat solenoid faulty.
J. low compression.
Engine can't be stopped. 1. Faulty shut-off lever at engine.
NOTE:
The engine
s
electrical system is protected by a 20-
Ampere manual reset circuit breaker located on the bracket
on [he left side of [he engine. The preheat solenoid is
moullled on lhe same bracket.
VerificationJRemedy
1. Check switch and/or battery connections.
2. Reset breaker; if breaker trips again. check preheat solenoid
circuit and check Circuit for shorts to ground.
J. Check voltage at and after breaker.
4. Check
(+)
connection to starier solenoid and (-) connection to
engine ground stud. Check battery cable connections.
5. Check solenoid.
1. Check connection at solenoid.
2.
Check switch with ohmmeter.
J. Check that 12 volts are present at starter solenoid activation
connection.
4. Check (+) connection to starter solenoid and (-) connectIOn to
engine ground stud. Check battery cable connections.
5. Check battery charge state.
1. Check that fuel valves are open.
2. Check solenoid.
J. Compression test the engine.
1. Reconnect shut off lever
2. Push-pull shut off cable from steering 2. Reconnect push-pull cable.
station to engine disconnected.
Engine stops. 1. Fuelhft pump failure.
1. Fuel lift pump should make a distinct ticking sound. Replace
pump with spare.
2. Switches and/or wiring loose 2. Inspect wiring for short circuits and loose connections.
or disconnected. Inspect switches for proper operation.
J. Fuel starvation. J.
Check fuel supply, fuel valves, fuel lift pump.
4. 20 Amp circuit breaker tripping.
4. Check for high DC amperage draw during operation
Ensure breaker is not overly sensitive to heat which would
cause tripping.
5. Exhaust system is restricted. 5. Check for blockage. collapsed hose, carbon buildup at
exhaust elbow.
6. Water in fuel.
6. Pump water from fuel tank{s); change filters and
bleed fuel system.
Battery not charging 1. Alternator drive. 1. Check drive belt tension. Aternator should turn freely. Check
for loose connections. Check output with voltmeter. Ensure 12
volts are present at the Exc terminal
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