Pontiac Fiero 1988 Service Manual page 406

CHARGING SYSTEM 6D3-1
SECTION 6 D 3
C HI A
G SYST
CONTENTS
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General Description
6D3-1
Charging System - CS 6D3-1
Diagnosis
.... 6D3-1
Charging System - CS 6D3-1
Service Procedures
6D3-2
Charging System 6D3-2
Generator Bench Check - CS 6D3-2
On-Car Service
6D3-3
Generator 6D3-3
Specifications ................................................ 6D3-4
Unit Repair 6D3-5
GENERAL DESCRIPTIOS
The engine electrical system includes the battery,
ignition (primary and secondary), starter (and related
wiring) and the generator (and related wiring).
Diagnostic charts (see Section 6D) will aid in
trouble-shooting system faults. When a fault is traced
to a particular component, refer to that components
5
section of the service manual.
CHARGING SYSTEM-CS
The CS Charging System has several sizes
available, including the CS-130 and CS-144. The
number (130 or 144) denotes the OD in mm of the
stator laminations.
CS generators use a new type regulator and a
diode trio is not used. A delta stator, rectifier bridge,
and rotor with slip rings and brushes are electrically
similar to earlier generators. A conventional pulley and
fan is used and, on the CS-130, an internal fan cools the
slip ring end frame, rectifier bridge and regulator.
Unlike three-wire generators, the CS-130 and
CS-144 may be used with only two connections -
battery positive and an "L" terminal to the charge
indicator bulb. Use of "P", "F", and "S" terminals is
optional. The "P" terminal is connected to the stator,
and may be connected externally to a tachometer or
other device. The "F" terminal is connected internally
to field positive, and may be used as a fault indicator.
The "S" terminal may be connected externally to a
voltage, such as battery voltage, to sense voltage to be
controlled.
As on other charging systems, the charge
indicator lights when the switch is closed, and goes out
when the engine is running. If the charge indicator is
on with the engine running, a charging system defect
is indicated. For all kinds of defects, the indicator will
glow at full brilliance, not "half lit". Also, the charge
indicator will be on with the engine running if system
voltage is too high or too low. The regulator voltage
setting varies with temperature, and limits system
voltage by controlling rotor field current.
This regulator switches rotor field current on and
off at a fixed frequency of about 400 cycles per second.
By varying the on-off time, correct average field
current for proper system voltage control is obtained.
At high speeds, the on-time may be 10% and the
off-time 90%. At low speeds, with high electrical loads,
on-off time may be 90% and 10%, respectively.
No periodic maintenance on the generator is
required.
DIAGNOSIS
CHARGING SYSTEM - CS
A basic wiring diagram for the CS charging
system is shown in Service Procedures. When
operating normally, the indicator lamp will come on
when the switch is turned on and go out when the
engine starts. If the lamp operates abnormally, or if an
undercharged or overcharged battery condition occurs,
the following procedure may be used to diagnose the
charging system. Remember that an undercharged
battery is often caused by accessories being left on
overnight, or by a defective switch which allows a
lamp, such as a trunk or glove box lamp, to stay on.
Also, this generator does not have a test hole.
To diagnose the CS-130 and CS-144 charging
systems, use the following procedure:
1. Visually check belt and wiring.
2. For vehicles without charge indicator lamp, go to
step 5.
3. With switch on, engine stopped, lamp should be
on. If not, detach harness at generator, and
ground "L" terminal.
a Lamp lights, replace or repair generator,
b Lamp does not light, locate open circuit
between grounding lead and ignition switch.
Lamp may be open.
4. With switch on, engine running at moderate
speed, lamp should be off. If not, detach wiring
harness at generator.
a. If lamp goes off, replace or repair generator.
If lamp stays on, check for grounded
terminal wire in harness.
5.
Battery undercharged or overcharged.
a. Detach wiring harness connector from
generator.
b. With switch on, engine not running,
connect voltmeter from ground to "L"
terminal.