Diagnosis And Testing - Dodge ram truck 3500 1996 Service Manual

BATTERY 8A - 3
D E S C R I P T I O N ANP O P E R A T I O N ( C o n t i n u e d !
inner wheelhouse panel. A plate with two studs
passes through the front of the tray and wheelhouse
panel from the top. A second plate with two studs
passes through the rear of the tray and wheelhouse
panel from underneath. Nuts are used to secure each
of the four exposed studs.
Models with the diesel engine option have a second bat­
tery tray located in the right front corner of the engine
compartment. This tray, and its mounting method and
hardware, is a mirror image of the left battery tray.
A hole in the bottom of the left battery tray is fit­
ted with a battery temperature sensor on some mod­
els. Models without the battery temperature sensor
have a plug fitted to this hole. Refer to Group 8C -
Charging System for more information on the battery
temperature sensor.
Models with an optional vehicle speed control sys­
tem have the speed control servo mounting bracket
attached to the bottom of the left battery tray. Refer
to Group 8H - Vehicle Speed Control System for more
information.
DIAGNOSIS AND TESTING
BATTERY
The battery must be completely charged and the top,
posts, and terminal clamps should be properly cleaned
before diagnostic procedures are performed. See Battery
Charging in this group for more information.
NOTE; Models equipped with the diesel engine option
are equipped with two 12-volt batteries, connected in
parallel (positive-to-positive/negative-to-negative). The
secondary battery, on the passenger's side, is dedi­
cated to providing current for the operation of the
intake manifold air heater. The primary battery, on the
driver's side, is dedicated to all other vehicle electrical
requirements. In order to ensure accurate diagnostic
results, these batteries MUST be disconnected from
each other, as well as from the vehicle electrical sys­
tem, when being tested.
WARNING:
• IF THE BATTERY SHOWS SIGNS OF FREEZ­
ING, LEAKING, LOOSE POSTS, OR LOW ELECTRO­
LYTE LEVEL, DO NOT TEST, ASSIST BOOST, OR
CHARGE. THE BATTERY MAY ARC INTERNALLY
AND EXPLODE. PERSONAL INJURY AND/OR VEHI­
CLE DAMAGE MAY RESULT.
• EXPLOSIVE HYDROGEN GAS FORMS IN AND
AROUND THE BATTERY DO NOT SMOKE, USE FLAME,
OR CREATE SPARKS NEAR THE BATTERY. PERSONAL
INJURY AND/OR VEHICLE DAMAGE MAY RESULT.
• THE BATTERY CONTAINS SULFURIC ACID,
WHICH IS POISONOUS AND CAUSTIC. AVOID CON­
TACT WITH THE SKIN, EYES, OR CLOTHING. IN
THE EVENT OF CONTACT, FLUSH WITH WATER
AND CALL A PHYSICIAN IMMEDIATELY. KEEP OUT
OF THE REACH OF CHILDREN.
• IF THE BATTERY IS EQUIPPED WITH REMOV­
ABLE CELL CAPS, BE CERTAIN THAT EACH OF
THE CELL CAPS IS IN PLACE AND TIGHT BEFORE
THE BATTERY IS RETURNED TO SERVICE. PER­
SONAL INJURY AND/OR VEHICLE DAMAGE MAY
RESULT FROM LOOSE OR MISSING CELL CAPS.
The condition of a battery is determined by two cri­
teria:
1. State-Of-Charge - This can be determined by
viewing the built-in test indicator, by checking the spe­
cific gravity of the electrolyte (hydrometer test), or by
checking the battery voltage (open circuit voltage test).
2. Cranking Capacity - This can be determined by
performing a battery load test, which measures the abil­
ity of the battery to supply high-amperage current.
First, determine the battery state-of-charge. This
can be done in one of three ways. I f the battery has a
built-in test indicator, use this test to determine the
state-of-charge. I f the battery has no test indicator,
but has removable cell caps, perform the hydrometer
test to determine the state-of-charge. I f the cell caps
are not removable, or a hydrometer is not available,
perform the open circuit voltage test to determine the
state-of-charge.
The battery must be charged before proceeding
with a load test if:
• The built-in test indicator has a black or dark
color visible.
• The temperature corrected specific gravity is
less than 1.235.
• The open circuit voltage is less than 12.4 volts.
A battery that will not accept a charge is faulty,
and must be replaced. Further testing is not
required. A fully-charged battery must be load tested
to determine its cranking capacity. A battery that is
fully-charged, but does not pass the load test, is
faulty and must be replaced.
NOTE: Completely discharged batteries may take
several hours to accept a charge. See Charging A
Completely Discharged Battery in this group for
more information.
A battery is fully-charged when:
• All cells are gassing freely during charging.
• A green color is visible in the sight glass of the
built-in test indicator.
• Three corrected specific gravity tests, taken at 1-hour
intervals, indicate no increase in the specific gravity.
• Open circuit voltage is 12.4 volts or greater.