Operation-Diagnosis; Alternator With Built-In Regulator; Diagnosing Problems - Winnebago 1987-1989 LeSharo Service Manual

ALTERNATOR
OPERATION - DIAGNOSIS
ALTERNATOR
WITH
BUILT-IN REGULATOR
These vehicles have alternators with a built-in
regulator. The warning light works as follows:
it is illuminated as soon as the ignition is
switched on.
- it goes out as soon as the engine starts.
- there is a failure in the charging circuit if it
illuminates while the engine is running.
Diagnosing Problems
WARNING
Disconnect the battery and regulator if any
electric arc welding is to be done on the vehicle.
Checking the current:
- Connect a voltmeter across the battery
terminals and read of the battery current
Start the engine and increase the revs. until the
voltmeter needle remai ns steady on the
regulated current figure. This should be
between 13.5 and 1sv.
Switch on as many accessories as possible; the
controlled current should remain steady
between 13.5 and 1Sv.
If the warning light does not illuminate when
the ignition is switched on, check for:
- broken alternator drive belt,
- broken charging wire,
- internal alternator failure (rotor, starter,
diodes or brushes),
- faulty regulator.
If the customer complains of a charging failure
although the warning light functions correctly:
- check the regulator if the regulated current is
less than 13.Sv. The problem may be due to:
- a faulty diode,
- a severed phase,
- or carboned-up tracks.
The regulator should be replaced only after the
first 3 possibilities have been checked and found
correct.
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