defective switches, or accessories. This condition of
discharge leads to a frequently rundown battery and starting
failure complaints. Turn the vehicle ignition switch to OFF.
Lights and accessories must be OFF and doors closed.
Observe the AMMETER scale. If the ammeter scale reads
zero, there are no short or grounded circuit paths for current,
in which case the electrical system is okay and all tests are
completed. If the ammeter scale reads other than zero, an
electrical short or grounded circuit exists if all the vehicle
circuits are turned OFF. The short or grounded circuit may
be found by isolating each circuit, one at a time, until the
ammeter reads zero. The last circuit isolated, as the ammeter
returned to zero, is the defective one. Many circuits can be
isolated by removing the circuit& from the fuse panel.
When you finish the test, shut the engine down
and turn the ignition switch to the OFF position
before disconnecting any test leads.
Reconnect the ground cable to the ground post of
the battery, and make sure all vehicle wires disconnected
during the testing are again securely and properly
ALTERNATOR USING THE ENGINE
Normally, when an engine analyzer (fig. 4-15)
is available for use, it is in the electrical shop. The
following information explains how to use the
analyzer to test alternators. In considering this
information, remember the following points:
(1) the example shown is one of several
manufactured, (2) the analyzer will do much more
than just test alternators, and (3) ALWAYS refer to
the manufacturers manual of the analyzer and the
unit being tested before making any connections.
Figure 4-15.-Engine analyzer.