Alternators And Generators; Household Batteries - Calterm 66430 Manual Del Propietário

Touch the negative (-) probe of the multimeter to the (-)
negative battery terminal and the positive (+) probe of the
multimeter to the positive (+) terminal of the battery. To
prevent the engine from starting, disconnect the coil
secondary wire from the center of the distributor cap and place
it against the engine block. On HEI distributors, remove the
connector from the terminal marked "BAT" to keep the engine
from starting. On DIS or electronic ignition systems remove
the connector going into the ignition module or modules. With
the ignition disabled, parking brake fully engaged, and manual
transmission in N (neutral) or automatic transmission in P
(Park), have an assistant crank the engine while you read the
meter. Only crank the engine long enough to obtain a fairly
steady reading on the multimeter. On a warm engine the
cranking voltage should be above 9.6 volts when the engine is
cranking at normal speed. If the voltage drops below 9.6 volts
while cranking the engine the battery needs to be charged. If
the battery is fully charged and still dropped below 9.6 volts
the battery should be load tested with a load tester and will
likely need replacement. Reattach wire to distributor or
ignition module after completing this test.
4.1d Battery Drain Test (DC Amps)
This test determines if an excessive constant drain on the
battery is present. Remove the negative terminal from the
battery. Turn off all accessories in the vehicle, REMOVE THE
IGNITION KEY FROM THE IGNITION, and remove the
underhood lamp. Disconnect the black (-) negative cable from
the battery. Set the function selection dial on the multimeter to
the 2000m setting for DC A. Touch one lead to the negative
battery cable end and one lead to the negative battery
terminal. After confirming that the reading is less than 200mA
the selection dial may be changed to the 200m setting for DC
Amps. If the reading is less than 20mAmps set the function
dial to the 20m DC A setting. Normal parasitic load exists
from accessory circuits including: ABS, remote keyless entry,
anti-theft systems, radio, CD changer, fog lamps, and the
powertrain control module. Compare the reading on the meter
to the specifications provided by the vehicle's manufacturer.
As a general rule the normal parasitic load on most vehicles
with all accessories off and the key removed from the ignition
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should not exceed 15 milliamps. Check your vehicle's
specifications to determine acceptable parasitic load. If the
reading is beyond the specified limit, begin removing fuses in
a systematic way while watching the reading on the
multimeter. When the removal of a fuse causes the reading to
drop, you have identified that one or more of the circuits
protected by the fuse is a source of the drain on the battery.

4.2 Alternators and Generators

Set the function/range switch to the 20 volt DC range. While
the engine is idling at normal operating speed, touch the black
(-) test lead to the metal framework of the vehicle, then touch
the red (+) test lead to the output terminal connector. The
alternator output cable is always the heaviest gauge cable
attached to the alternator (see fig. 2). The display should read
12 volts or more. If the display fluctuates rapidly, the cable
may need to be tightened. If the engine is idling lower than is
specified in the vehicle owners manual, the voltage reading
will be lower. If the output voltage is significantly low, the
alternator may require service or replacement.
! WARNING When making automotive measurements,
observe safety precautions. Stay away from the fan blades,
belts and other moving parts of the engine. Keep the
multitester and its leads away from moving parts. Always fully
engage the parking brake and place the automatic transaxle in
P (Park) or manual transaxle in N (Neutral) before performing
tests with the engine running.

4.3 Household Batteries

Set the function/range switch to the 20 volt DC setting. Touch
the red (+) lead to the (+) terminal of the battery and the black
(-) lead to the (-) terminal of the battery. Read the voltage level
of the battery on the display. Generally speaking, if a battery's
output voltage falls below 60% - 70% of its original rating, it
should be replaced.
Figure 2
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