Troubleshooting; Test Equipment - Briggs & Stratton 405777 Series Manual

The following list is provided to aid you in diagnosing problems with alternator systems.
COMPLAINT
"Battery not charging"
"Battery in state of
overcharge"
"Headlamps not working"
"Electric clutch not working"
(Tri-Circuit Alternator)

TEST EQUIPMENT

The following equipment is recommended to test and
repair alternators.
Digital Multimeter
The Digital Multimeter is available from your Briggs &
Stratton source of supply. Order as Tool #19464. The meter
may be used to read volts, ohms or amperes, and test
diodes, when leads are inserted in the appropriate
receptacle, Fig. 8.
The Digital Multimeter will withstand DC input of 10-20
amps for up to 30 seconds. When checking DC output on
16 and 20 amp regulated system, use the DC shunt, Tool
#19468, to avoid blowing fuse in meter, Fig. 9.
NOTE: The Digital Multimeter is equipped with two fuses to
prevent damage to the meter in the event that the input
limits are exceeded. If the meter displays a reading of 0.00
when testing DC output (
Refer to FLUKE Operators Manual for procedure for
checking fuses. Replacement fuse is available from your
Briggs & Stratton source of supply. Order Part No. 19449 or
19571.

TROUBLESHOOTING

• Engine RPM too low.
• Inline fuse "blown" (if equipped).
• Defective battery.
• Loose, pinched, or corroded battery ground leads.
• Loose, pinched, or corroded battery charge leads.
• Open, shorted, or grounded wires between output connector and battery.
• Defective diode (open or shorted).
• Defective or improperly grounded regulator-rectifier.
• Diode installed incorrectly (reversed).
• Damaged battery (shorted battery cells).
• Excessive current draw from accessories.
• Low magnetic flux or damaged alternator magnets.
• Severe battery vibration (missing or broken tie-down straps).
• Battery rate of charge not matched to alternator output.
• Damaged battery (shorted battery cells).
• Defective regulator.
• One OHM resistor shorted or grounded (Tri-Circuit system only).
TSM
• Inline fuse "blown" (if equipped).
• Defective headlamps.
• Loose or corroded wires.
• Open, shorted or grounded wires between output connector and headlamps.
• Light switch defective.
• Defective diode Tri-Circuit system (open or shorted − white output lead side).
• Low magnetic flux or damaged alternator magnets.
• Inline fuse "blown" (if equipped).
• Loose or corroded wires.
• Open, shorted or grounded wires between output connector and electric clutch.
• Defective diode (open or shorted-red output lead side).
• NOTE: Battery will also not charge.
• Defective electric clutch switch.
• Open, shorted or grounded clutch circuit.
• Low magnetic flux or damaged alternator magnets.
), check fuses in meter.
POSSIBLE CAUSES
Testing Alternator Output
When checking alternators, make the tests in the following
sequence.
1. Test alternator output.
2. Test diode(s) or regulator, rectifier (if equipped).
Fig. 8 − Digital Multimeter
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