Jeep Cherokee XJ 1999 Manual - page 13
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes.
(2) Determine that the under-hood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable
clamp and the battery negative terminal post. Make
sure that the doors remain closed so that the illumi-
nated entry system is not activated. The multi-meter
amperage reading may remain high for up to three
minutes, or may not give any reading at all while set
in the highest amperage scale, depending upon the
electrical equipment on the vehicle. The multi-meter
leads must be securely clamped to the battery nega-
tive cable clamp and the battery negative terminal
post. If continuity between the battery negative ter-
minal post and the negative cable clamp is lost dur-
ing any part of the IOD test, the electronic timer
function will be activated and all of the tests will
have to be repeated.
(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment on the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Power Distribution Center (PDC) and
then in the junction block (refer to Power Distribu-
tion Center and Junction Block in the Component
Index of Group 8W - Wiring Diagrams for fuse and
circuit breaker identification) one at a time until the
amperage reading becomes very low, or nonexistent.
This will isolate each circuit and identify the source
of the high-amperage IOD. If the amperage reading
remains high after removing and replacing each fuse
and circuit breaker, disconnect the wire harness from
the generator. If the amperage reading now becomes
very low or nonexistent, refer to Charging System
in the Diagnosis and Testing section of Group 8C -
Charging System to diagnose the condition. After the
high-amperage IOD has been corrected, switch the
multi-meter to progressively lower amperage scales
and, if necessary, repeat the fuse and circuit breaker
remove-and-replace process to identify and correct all
sources of excessive IOD. It is now safe to select the
lowest milliampere scale of the multi-meter to check
the low-amperage IOD.
CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed twenty-five milliam-
peres (0.025 ampere). If the draw exceeds twenty-five
milliamperes, isolate each circuit using the fuse and
circuit
breaker
remove-and-replace
process.
The
multi-meter reading will drop to within the accept-
able limit when the source of the excessive draw is
disconnected. Repair this circuit as required; whether
a wiring short, incorrect switch adjustment, or a
component failure is at fault.
SERVICE PROCEDURES
BATTERY CHARGING
A battery is fully-charged when:
•
All cells are gassing freely during battery charg-
ing.
•
A green color is visible in the sight glass of the
built-in test indicator.
•
Three hydrometer tests, taken at one-hour inter-
vals, indicate no increase in the temperature-cor-
rected specific gravity.
•
Open-circuit voltage is 12.4 volts or above.
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.
XJ
BATTERY
8A - 13
DIAGNOSIS AND TESTING (Continued)