Check In Car; Rotor - Pontiac Grand Prix Service Manual

ENGINE ELECTRICAL
6E-7
1. Do not attempt to polarize generator. It is not
necessary since there are no permanent magnets.
2. Do not short across or ground any terminals on
generator.
3. Never operate generator on open circuit (with field
terminal connected and output terminal disconnected).
Make absolutely certain all connections in circuit are
secure. If generator is operating on open circuit,
extremely high voltages may result that .are both
dangerous and damaging to generator.
4. When installing battery, make absolutely sure
negative post is attached to ground strap.
CAUTION: Never reverse battery leads, even for an
instant,
as
reverse polarity current flow will damage
diodes in generator.
5. When connecting booster battery, make certain to
connect negative battery terminals together and posi-
tive battery terminals together.
6. When connecting charger to battery, connect
charger positive lead to battery positive terminal and
charger negative lead to battery negative terminal.
CHECK IN CAR
If electrical system is not charging properly, follow the
in-car checks outlined in Charging Circuit Preliminary
Checks, Figs. 6E-19 and 6E-21 in the Diagnosis
Manual, prior to removing generator. Remove genera-
tor as follows:
REMOVE FROM CAR
1. Disconnect positive battery terminal.
CAUTION: Failure to observe this step may result in an
injury fiom hot battery lead at generator.
2. Remove two leads at generator.
3. Loosen adjusting bolts.
4. Remove generator drive belt.
5. Remove bolts which retain generator.
6. Remove generator from car
DISASSEMBLE GENERATOR
1. If rotor, drive end frame bearings or pulley and fan
need replacement, remove and replace shaft nut using
Allen wrench.
3. Remove four through bolts.
4. Separate drive end frame and rotor assembly from
stator assembly by prying apart with screwdr; lver at
stator slot. The fit between the two is not tight and the
two can be separated easily.
NOTE: The separation is to be made between stator
assembly and drive end frame.
CAUTION: As rotor and drive end frame assembly is
separated fiom slip ring frame assembly, the brushes will
fall down onto shaft and come in contact with lubricant.
Brushes which come in contact with shaft should be
cleaned immediately to avoid contamination by oil, or
they will have to be replaced,
INSPECTION AND REPAIR
ROTOR
The rotor may be checked electrically for grounded,
open or short-circuited field coils as follows:
1. To check for grounds, connect a 110-volt test lamp
or ohmmeter from either slip ring to rotor shaft, or to
rotor poles. If lamp lights or ohmmeter leading is low,
the field winding is grounded (Fig. 6E-11).
4
2. To check for opens, connect test lamp or ohmmeter
to each slip ring. If lamp fails to light or if the
ohmmeter reading is high (infinite), winding is open
(Fig. 6E-11).
(CHECK FOR GROUNDS)
I
OHMMETEE
OHMMETER
(CHECK FOR OPENS)
2. Scribe a mark between two halves of generator to
help locate parts in same position during assembly.
Fig. 6E.11 Checking Rotor