Installation manual

DC ELECTRICAL SYSTEM! ALTERNATOR
E. Now check the voltage between the alternator output
terminal (B+) and ground. If the circuit is good. the
voltage at the alternator should be the same as the bat-
tery, or if an isolator is in the circuit the alternator volt-
age will be zero. If not, a problem exists in the circuit
between the alternator and the battery. Check all con-
nections - look for an opening in the charging circuit.
STARTING BATTERY
@
ALTERNATOR
TESTING THE STARTING
BATIERY·ALTERNATOR
(ENGINE RUNNING)
...1
_"",,=--' ENGINE
GROUND
F. Start the engine again. Check the voltage between the
alternator output and ground.
The voltage reading for a properly operating alternator
should be between 13.5 and 14.5 volts. If your alterna-
tor is OVCf- or undercharging, have it repaired at a reli-
able service shop.
NOTE: Before removing rhe alternator for repair, usc your
voltmeter
to ensure that 12 volts DC excitaIioll is preselIf
at the EXC terminal if the pn::l'ious test showed only hat-
tery voltage at the B oUlput terminal.
If 12 volts is not presenl at the EXC lerrninallrace the
wiring, look for breaks alld poor connections.
Alternator is Working
4. Check the voltage of the service battery. This battery
should have a voltage between
13 and 14 volts when the
engine
is running. If not, there is a problem in the service
battery charging circuit. Trouhle-shoot the service battery
charging circuit by checking the wiring and connections,
the solenoid, isolator, battery switch and the battery itself.
MUlTiMETER
BAnERY SWITCH /'> ~t
SERVICE
BATTERY
~:::::::::;::;;--- TESTING THE SERVICE
BATIERY (ENGINE RUNNING)
it. CAUTION: When performing tests on the alterna·
tor charging circuit do not use a high voltage tester fie
Megger}. You can damage the alternator diodes.
"'loY' WES7ERBEKE
Engines & Generators
23