Pontiac Fiero 1988 Service Manual page 387

6D1-2 BATTERY
3. The vehicle's electrical load is more than the
generator output, particularly with the addition
of aftermarket equipment.
4. Defects in the charging system such as electrical
shorts, slipping fan belt, faulty generator, or
faulty voltage regulator.
5. Battery abuse, including failure to keep the
battery cable terminals clean and tight, or loose
battery hold-down. See "Service Procedures" for
torque specifications.
6. Mechanical problems in the electrical system,
such as shorted or pinched wires.
Electrolyte Freezing
The freezing point of electrolyte depends on its
specific gravity. Since freezing may ruin a battery, it
should be protected against freezing by keeping it in a
charged condition.
Carrier and Hold-Down
The battery carrier and hold-down clamp should
be clean and free from corrosion before installing
battery.
The carrier should be in sound condition, to hold
the battery securely and keep it level. Make certain
there are no parts in the carrier before installing
battery.
To prevent the battery from shaking in its carrier,
the hold-down bolts should be tight, but not
overtightened.
Built-in Hydrometer
The sealed battery has a built-in, temperature
compensated hydrometer in the top of the battery. This
hydrometer is to be used with the following diagnostic
procedure.
When observing the hydrometer, make sure that
the battery has a clean top. A light may be required,
if the lighting is poor.
Under normal operation, two indications can be
observed (see Fig. 4).
1. GREEN DOT VISIBLE
Any green appearance is interpreted as a "green
dot" and the battery is ready for testing.
2. DARK; GREEN DOT NOT VISIBLE
If there is a cranking complaint, the battery
should be tested as described in the "Diagnosis"
section. The charging and electrical system
should also be checked at this time.
Occasionally, a third condition may appear:
3. CLEAR OR LIGHT YELLOW
This means the fluid level is below the bottom of
the hydrometer. This may have been caused by
excessive or prolonged charging, a broken case,
excessive tipping, or normal battery wearout.
Finding a battery in this condition may indicate
high charging voltages caused by a faulty
charging system. Therefore, the charging and
electrical systems may need to be checked. If a
cranking complaint exists and is caused by the
DIAGNOSIS
BATTERY
1. VISUAL INSPECTION
Check for obvious damage, such as cracked or
broken case or cover, that could permit loss of
electrolyte. If obvious damage is noted, replace
the battery. Determine cause of damage and
correct as needed. If not, proceed to step 2.
2. HYDROMETER CHECK
a. GREEN DOT VISIBLE - Go To Step 3
b. DARK; GREEN DOT NOT VISIBLE -
Charge the battery as outlined under
"Charging Procedure" section and proceed
to Step 3.
3. LOAD TEST
Load testing may require use of battery side
terminal adapters to insure good connections (see
Fig. 2).
a. Connect a voltmeter and a battery load
tester across the battery terminals.
b. Apply 300 ampere load for 15 seconds to
remove surface charge from the battery.
Remove load.
c. Wait 15 seconds to let battery recover and
apply specified load from specifications.
Read voltage after 15 seconds, then remove
load.
d. If voltage does not drop below the minimum
listed in Fig. 3, the battery is good and
should be returned to service. If voltage is
less than minimum listed, replace battery.
(The battery temperature must be estimated
by feel and by the temperature the battery
has been exposed to for the preceding few
hours.)
' S E R V I C E P R O C E D U R E S
BATTERY CHARGING
When it is necessary to charge the battery, the
following basic rules must be followed:
H 2 Q 2 5 3 - 6 D
Fig. 2 Side Terminal Battery Adapters