Bolens 131-730A - Manual (Page 17)

TROUBLE SHOOTING CHART FOR ELECTRIC START MODELS
TROUBLE LOOK FOR REMEDY
Engine will not
crank
Battery installed incor­
rectly
The battery must be installed with the negative, identified at the term nal post by (Neg, N or -),
grounded. The positive (Pos, P or -t-) attaches to the large cable from the solenoid. The small
red wire from the fuse holder or circuit breaker is also attached to the positive terminal.
Blow fuse or circuit
breaker
Replace fuse with IVi amp. fuse Va x 1 Va ” Ig. Circuit breaker will reset itself when it cools off.
Fuses or circuit breakers seldom open or fail without a reason. The problem must be corrected.
Check for loose connections in the fuse holder. Replace fuse holder if necessary. A dead short
may be in the cranking or charging circuit where the insulation may have rubbed through and
exposed the bare wire. Replace the wire or repair with electrican’s tape if the wire strands have
not been damaged. Note: Look for a wire pinched between body panels, burned by the ex­
haust pipe or muffler or rubbed against a moving part.
Battery is dead or weak Use a hydrometer to check the condition of the battery. The Specific Gravity (s.g.) should be
1.265 at 80°F. (1.215 s.g. minimum needed for cranking engine). The reason for the battery fail­
ing must be determined. (1) Defective battery. Battery will not accept or hold a full charge. (2)
Short circuit. Check for grounded wire. (3) Charging system not working, either engine alter­
nator or trickle charger.
Trickle Charger. Check with multimeter. Charger 725-0578—input 120 V A.C., no load output
13.5 V D.C., rated load current 1 amp. Charger 725-0507—input 120 V A.C., no load output 17.4
V D.C., rated load current 1/2 amp.
Alternator (dual or single circuit) The charging system is an alternator located under the
flywheel. It is unregulated and rated 3 amp. at 3600 r.p.m. A diode (rectifier) is located in the
output lead just before the wire harness plug on the engine side.
To Alternator
0
:;
The diode changes A.C. to D.C. to charge the battery. A bad diode can either fail to charge the
battery or discharge the battery if the alternator is shorted as well as the diode. To test: (1)
Disconnect charger lead from the battery (small red wire). (2) Connect 12 V small test lamp bet­
ween the 3 amp. D.C. charge lead and the positive terminal of the battery. (3) With the engine
off, the lamp should not light. If it does, the diode and possibly the alternator should be replac­
ed. (4) Start the engine. The lamp should light. If it does not,the alternator (stator) or lead wire
is bad and should be replaced.
Mechanical failure.
(Wires and switches)
The interlock system includes two mechanical activated switches which are wired in series in
the circuit used to energize the starter solenoid. While testing the interlock system, you will
make the mower temporarily unsafe by permitting the engine to be started with the blade and
clutch engaged. WARNING: While testing, disengage the clutch, shut off the blade control, set
the parking brake and place the gear shift lever in neutral. Attach a wire (minimum 18 gauge) to
the positive terminal of the battery and touch the other end to the small terminal on the
solenoid. If the engine does not crank: (1) There is a loose connection or poor ground. (2) The
solenoid may be bad. The solenoid can be checked by using a heavy wire (#8 gauge minimum)
and jumping between the two large terminals. If the engine cranks, the solenoid is bad. (3) If
the engine does not crank when you jump the solenoid, have the starter motor tested by an
authorized engine dealer. If the engine does crank, the problem is with one of the safety swit­
ches, ignition switch or the wire between the fuse holder (or circuit breaker) and the small ter­
minal on the solenoid. Note: Look for a poor connection at the switches or a defective switch.
Replace if necessary.
Engine cranks
but will not
start
Throttle or choke not in
starting position Check owner’s guide for correct position for throttle control and choke (if separate control) for
starting.
17