Chevrolet 1977 light duty truck, Service Manual

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I N S T A L L I N G B A T T E R I E S
To install a battery properly, it is im portant to observe
the following precautions:
• Connect grounded term inal of battery last to avoid
short circuits which may damage the electrical system. Do
not connect prim ary lead until secondary negative cable wire
has been grounded to sheet metal.
• Be sure there are no foreign objects in the carrier, so
th at the new battery will rest properly in the bottom of the
carrier.
• Tighten the hold-down evenly until snug (60-80 in.
lbs.). Do not draw down tight enough to distort or crack the
case or cover.
• Be sure the cables are in good condition and the
term inal bolts are clean and tight. Make sure the ground
cable is clean and tight at engine block or frame.
• Check polarity to be sure the battery is not reversed
with respect to the generating system.
Do not over torque cable terminal studs.
Replacement
1. Disconnect battery negative cable and then the
positive cable.
2. Remove battery hold-down clamp bolt and clamp.
3. Remove battery from tray.
4. Position new battery, which has been properly
activated, in the battery tray.
5. Install battery hold down clamp and bolt.
N O T E : Recommended hold-down bolt torque is 70 in.
lbs.
6. Install battery positive and negative cables and tighten
term inal bolts to 70 in. lbs. torque.
DIAGNOSIS
BATTERY TEST PROCEDURE
To determ ine the ability of a battery to function properly
requires testing. The accuracy of the testing changes with
tem perature, specific gravity, age of the battery, etc.
Therefore, an accurate test has more than one step:
Step 1. Visual inspection.
Step 2. Specific gravity check (hydrometer)
Step 3. Program m ed Instrum ent Test
Step 4. Load Test.
C A U T I ON :
Wear safety glasses. D o n o t break live
circuits a t battery terminals. When testing be
certain to rem ove gases a t battery cover caused by
charging.
MAINTENANCE
GENERAL IN F O R M A T IO N
The state of charge indicator located on top of the
battery (Fig. 6D-1B) is to be used with accepted diagnostic
procedures only. It is not to be used to determine if the
battery is good or bad, or charged or discharged. The
indicator is actually a built-in hydrom eter in one cell of the
battery and provides visual inform ation only for battery
testing.
On rare occasions, the state of charge indicator will turn
light yellow. Normally, a battery with this condition is
capable o f further service but the indicator can no longer
provide inform ation for battery testing. A light yellow
indicator is by no means a com m and to replace the battery.
However, if a problem exists, such as failing to crank, the
battery must be replaced. Do not charge, test or jum p start.
It is im portant when observing the state of charge
indicator, that the battery be relatively level and have a clean
indicator top to see the correct indication. An electric light
or flashlight may be required in some poorly-lit areas to verify
the correct indication. Under normal operation, two
indications can be observed:
G R E E N D O T V I S I B L E
Any green appearance in the indicator is interpreted as
a "green dot" and the battery is ready for testing. On rare
occasions following prolonged cranking, the green dot may
still be visible even though the battery is in a discharged
condition. Should this occur, charge battery as described in
Charging Procedure portion of this manual.
FREE BATTERY
D A R K - G R E E N D O T N O T V I S I B L E
If there is a cranking complaint, the battery should be
tested as described in the Testing Procedure that follows:
TESTING PROCEDURE
V I S U A L I N S P E C T I O N
Check for obvious damage, such as cracked or broken
case or cover, that could permit loss of electrolyte. If obvious
physical damage is noted, replace battery. Determine cause
of damage and correct as needed.
S T A T E O F C H A R G E I N D I C A T O R (Fig. 6 D - 1 B )
Green Dot Visible
If the indicator is dark and has a green dot in the center,
the battery is OK for testing. Proceed to step 3. On rare
occasions, such as after prolonged cranking, the green dot
may still be visible even though the battery is in a state of
discharge. Should this situation occur, charge battery as
described in Charging Procedure portion of this manual.
Dark-Green Dot Not Visible
If the indicator is dark but the green dot is not visible,
charge the battery as described in Charging Procedure
portion of this m anual and proceed to Remove Surface
Charge step.
Light or Yellow
On rare occasions the indicator will turn light yellow and
the battery must not be tested. Replace the battery. Do not
charge, test or jum p start.