Würth 0772 800 - Charging System Test; Cranking Voltage Analysis; Idle Voltage Check

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Charging system test (example)
SYSTEM TEST
××.×× V
If you press Enter the adjacent screen appears.
TURN OFF LOADS
START ENGINE
Turn o all vehicle accessory loads such as light, air conditioning, radio, etc.
before starting the engine.
When the engine is started, one of the following results will be displayed along
with the relevant reading.
CRANKING VOLTS
××.×× V NORMAL
Cranking volts normal
The system is showing a normal result. Press ENTER to perform the charging
system test.
CRANKING VOLTS
××.×× V LOW
Cranking volts low
The start voltage is below the normal values. Look for errors as recommended by
the manufacturer.
CRANKING VOLTS
NO DETECTED
Cranking volt no detected
The cranking voltage has not been detected.
PRESS ENTER FOR
CHARGING TEST
If the cranking voltage is normal, press Enter to begin charging system test.
MAKE SURE ALL
LOADS ARE OFF
If you press Enter the adjacent screen appears.
Press the Enter key and one of the three results will be displayed along with the
relevant reading.
ALT. IDLE VOLTS
××.××V LOW
Low charging volts when test at idle
The alternator is not providing sucient current to the battery.
Check the v-belts to ensure the alternator is rotating with engine running. If
the belts are slipping or broken, replace the belts and test again. Check the
connections from the alternator to the battery. If the connection is loose or heavily
corroded, clean or replace the cable and retest. If the belts and connections are
in good working condition, replace the alternator.
ALT. IDLE VOLTS
××.××V NORMAL
Charging system normal (test without loads)
The system is showing normal output from the alternator. No problem detected.
ALT. IDLE VOLTS
××.××V HIGH
Charging voltage high (test without loads)
The voltage output from the alternator to the battery exceeds the normal limits
of a functioning regulator. Check to ensure there is no loose connection and
the ground connection is correct. If there are no connection issues, replace the
regulator of the alternator. Since most alternators have the regulator built-in, this
will require you to replace the alternator. The normal upper limit of a typical auto-
motive regulator is 14.7 volts +/- 0.05. Check manufacturer specications for the
correct limit, as it will vary by vehicle type and manufacturer.