Dodge Durango (HB). Manual - part 254
4. Set an electronic digital multi-meter to its highest amperage scale. Connect the multi-meter between the discon-
nected battery negative cable terminal clamp and the battery negative terminal post. Make sure that the doors
remain closed so that the illuminated 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 in the vehicle. The multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the battery negative terminal post. If continuity between the battery
negative terminal post and the negative cable terminal clamp is lost during any part of the IOD test, the elec-
tronic 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 non-
existent, depending upon the electrical equipment in 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
(JB), one at a time until the amperage reading becomes very low, or nonexistent. Refer to the appropriate wiring
information in this service manual for complete PDC and JB fuse, circuit breaker, and circuit identification. This
will isolate each circuit and identify the circuit that is 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 for
the proper charging system diagnosis and testing procedures. 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-amperage IOD should not exceed thirty-five milliamperes (0.035
ampere). If the current draw exceeds thirty-five milliamperes, isolate each circuit using the fuse and circuit
breaker remove-and-replace process in Step 5. The multi-meter reading will drop to within the acceptable limit
when the source of the excessive current draw is disconnected. Repair this circuit as required; whether a wiring
short, incorrect switch adjustment, or a component failure is at fault.
OPEN-CIRCUIT VOLTAGE TEST
A battery open-circuit voltage (no load) test will show
the approximate state-of-charge of a battery. This test
can be used in place of the hydrometer test when a
hydrometer is not available, or for maintenance-free
batteries with non-removable cell caps.
Before proceeding with this test, completely charge
the battery (Refer to 8 - ELECTRICAL/BATTERY SYS-
TEM/BATTERY - STANDARD PROCEDURE).
1. Before measuring the open-circuit voltage, the sur-
face charge must be removed from the battery.
Turn on the headlamps for fifteen seconds, then
allow up to five minutes for the battery voltage to
stabilize.
2. Disconnect and isolate both battery cables, nega-
tive cable first.
3. Using a voltmeter connected to the battery posts
(see the instructions provided by the manufacturer
of the voltmeter), measure the open-circuit voltage.
See the Open-Circuit Voltage Table. This voltage reading will indicate the battery state-of-charge, but will not reveal
its cranking capacity. If a battery has an open-circuit voltage reading of 12.4 volts or greater, it may be load tested
to reveal its cranking capacity (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCE-
DURE).
HB
BATTERY SYSTEM
8F - 13