Gravely Convertible 10 Shop Manual page 25

posts are wound to provide energy for ignition. The ignition winding on the breakerless circuits are of very thin
wire which is covered by an epoxy - be careful when installing the flywheel not to touch the sharp edges against
the wires as they can be easily cut in spite of the protective covering.
SERVICE: No adjustments are possible on the alternator system and field service is not recommended. The faulty
part should be replaced by a new part. The Trouble Analysis Chart can be used to pinpoint the faulty part on a 15
amp system.
TESTS: There are only a few tests that can be applied to the charging circuit. If the battery is not being charged,
check out the battery first for cracked cells, etc., - if the battery proves to be in good condition, that is, the tests
reveal it is able to hold charge, the trouble is either in a faulty rectifier-regulator or in the stator windings. Check
stator per test procedures outlined in the accompanying trouble shooting chart.
The ignition circuit functions the same as previously described breakerless and/or battery ignition circuits and
should be tested or serviced the same way.
Since the rectifier-regulator will not work (SCR's cannot turn on) without a battery in the system, there are no
actual tests that can be performed on this unit with equipment in the field - it will either regulate as required or it
will not function at all. If it is not working, check to make sure that a good ground contact is made between
rectifier and vehicle or engine - often paint causes poor electrical path here.
PRECAUTIONS - 15 AMP SYSTEMS
1. Battery polarity must be correct. Negative ground systems are used with Kohler Engines.
2. Prevent alternator leads (AC) from touching or shorting. This could permanently damage the stator.
3. Disconnect leads at rectifier-regulator before electric welding is done on equipment in common ground
with engine.
4. Do not operate for any length of time without a battery in the system.
PRE-SERVICE PROCEDURE
1. Check to make sure that a good ground. is provided between the rectifier-regulator unit and the equipment.
This must be in common ground with the engine and battery. (See wiring diagrams)
2. Check for and correct poor connections or broken wires.
TEST WITH ENGINE RUNNING AT 3600 RPM - NO LOAD
CONDITION:
NO CHARGE TO BATTERY
TEST A -- With B+ cable connected, check B+ (at terminal
on rectifier-regulator) to battery was ground with DC
Voltmeter. If 13.8 volts fully charged.or higher, place
minimum load of 5* amps on battery to reduce voltage:
A-1 -- If charge rate increases.
A-2 -- If charge rate does not increase.
TEST B -- Unplug leads at rectifier-regulator, connect VOM
(multimeter) across AC leads, check AC voltage:
B-1 -- If less than 28 volts.
B-2 -- If more than 28 volts.
CONDITION:
BATTERY CONTINUOUSLY
CHARGES AT HIGH RATE
TEST C -- Check B+ to ground with DC Voltmeter:
C-1 -- If over 14.7 volts.
C-2 -- If under 14.7 volts.
"Turn lights on if 60 watts or more or simulate load by placing a 2.5 ohm 100 watt resistor across battery terminals.
TROUBLE SHOOTING -15 AMP SYSTEM
POSSIBLE FAULT/REMEDY
A-1 – Indicates alternator system OK. Battery was fully
charged
A-2 -- Check for defective stator or rectifier - regulator
TEST B)
B-1 -- Defective stator, replace with new assembly.
B-2 -- Defective rectifier-regulator, replace with new unit.
POSSIBLE FAULT/REMEDY
C-l -- Rectifier-regulator not functioning properly. Replace
with new unit.
C-2 -- Alternator system OK. Battery unable to hold charge.
Check specific gravity of battery. Replace if necessary.
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