MCi Crusader II 1989 Maintenance Manual page 233

Date 1-1-89 Page
7-13
MC-9 MAINTENANCE MANUAL
REGULATOR
AL TERNA TOR
BATTERY
Figure 7-27. Voltage Regulator Adjustment Setup.
VOLTAGE REGULATOR SETTING
To check the voltage setting. connect a voltmeter across the
POS and NEG terminals on the regulator and an ammeter at the
, DC terminal on the alternator (figure
7-27).
Operate the engine
'- at approximately 1,000 RPM (about 2.300 alternator RPM) with
accessories turned on to obtain 20-200 amperes alternator
output and note the voltage setting. The voltage should be
steady and reasonably c:ose to 272 volts. nominal Desiree
variations from the published setting can be obtained by remov-
ing the plug from the voltage regulator cover and turning the
ad1usting screw inside the regulator (figure 7-28). This will
change the voltage to meet the needs of vehicle as dictated by
operating conditions.
Figure 7-28. Adjusting Voltage Regulator.
If the voltage setting as checked above is steady and rea-
sonably close to the specified value and the battery is under-
charged. raise the setting by .3 volt and check for an improved
battery condition over a minimum service period of 48 hours. If
the voltage can not be adjusted to the desired value. the alterna-
tor should be checked as follows:
1
Stop alternator. tCJrn off all accessories and disconnect
battery ground cable.
2. Disconnect all leads from the alternator and from the
alternator field.
CAUTION: Do not allow leads to touch vehi-
cle ground.
3. Connect a voltmeter and ammeter in the circuit at the DC
terminal on the alternator.
4.
Connect a jumper lead from the alternator DC terminal to
the field terminal. If two field terminals are used, ground the
other field terminal.
5. Connect a carbon pile load across the battery. Turn to off
position. ·
6. See figure 7-29 for wiring connections.
7. Reconnect battery ground cable.
8. Turn on all vehicle accessories.
9. Operate alternator and adjust carbon pile load as required
for output of 80 amps at 1.200 RPM or 225 amps at 2,500 RPM
(cold).
10. Check the alternator field winding as follows:
REGULATOR
BATTERY
Figure 7-29. Alternator Output Test Setup.
Alternators with one field terminal Disconnect the lead
from the field terminal and connect an ohmmeter from the field
terminal to ground. For alternators with two field terminals.
disconnect all leads -from the field terminals and connect an
ohmmeter across the terminals.
A resistance reading above normal indicates an open. and a
resistance reading less than normal indicates a short or
ground. The normal resistance can be calculated by dividing
the indicated voltage by the field current rating of 5.95V ~.25V
The normal resistance value should be at or ne ..
ir
midscale on
the ohmmeter for accuracy.
An alternate method of checking is to connect a battery of
specified voltage and an ammeter 1n series with the field wind-
ing and compare readings with published spec1ficat1ons 1n
Delco-Remy Service Bulletin
1G-186. 1G-187
or
1G-188.
To check for a ground. connect the ohmmeter from either
field terminal to ground. A reading equal to or less than the
normal resistance value indicates a ground.
The alternator is defective if it does not produce rated output
or if field windings are faulty. If the alternator provides rated
output and field windings check satisfactorily. the regulator
should be checked as covered under Regulator Checks.
et