Dodge 2000 DURANGO Service Manual page 449

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DESCRIPTION AND OPERATION (Continued)
houses up to nineteen blade-type fuses (two stan-
dard-type and seventeen mini-type), up to two blade-
type automatic resetting circuit breakers, and two
International Standards Organization (ISO) relays
(one standard-type and one micro-type).
The molded plastic JB housing has integral mount-
ing brackets that are secured with two screws to the
left instrument panel end bracket. The left end of the
instrument panel cover has a snap-fit fuse access
panel that can be removed for service of the JB. A
fuse puller and spare fuse holders are located on the
back of the fuse access cover, as well as an adhesive-
backed fuse layout map to ensure proper fuse identi-
fication.
The JB unit cannot be repaired and is only ser-
viced as an assembly. If any internal circuit or the JB
housing is faulty or damaged, the entire JB unit
must be replaced.
OPERATION
All of the circuits entering and leaving the JB do
so through up to nine wire harness connectors, which
are connected to the JB through integral connector
receptacles molded into the JB housing. Internal con-
nection of all of the JB circuits is accomplished by an
intricate combination of hard wiring and bus bars.
Refer to Junction Block in the index of this service
manual for the location of complete JB circuit dia-
grams.
IGNITION-OFF DRAW FUSE
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse (Fig. 3) that is disconnected within
the Junction Block (JB) when the vehicle is shipped
from the factory. Dealer personnel are to reconnect
the IOD fuse in the JB as part of the preparation
procedures performed just prior to new vehicle deliv-
ery.
The left end of the instrument panel cover has a
snap-fit fuse access panel that can be removed to pro-
vide service access to the fuses in the JB. A finger
recess is molded into the access panel for easy
removal. An adhesive-backed fuse layout map is
secured to the instrument panel side of the access
panel to ensure proper fuse identification. The IOD
fuse is a 15 ampere mini blade-type fuse. The fuse is
secured within a black molded plastic fuse holder
and puller unit that serves both as a tool for discon-
necting and reconnecting the fuse in its JB cavity,
and as a fuse holder that conveniently stores the fuse
in the same JB cavity after it has been disconnected.
POWER DISTRIBUTION SYSTEMS
Fig. 3 Ignition-Off Draw Fuse - Typical
1 – JUNCTION BLOCK
2 – IGNITION-OFF DRAW FUSE AND HOLDER
3 – LEFT INSTRUMENT PANEL END BRACKET
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
fuse feeds the memory and sleep mode functions for
some of the electronic modules in the vehicle as well
as various other accessories that require battery cur-
rent when the ignition switch is in the Off position,
including the clock. The only reason the IOD fuse is
disconnected is to reduce the normal IOD of the vehi-
cle electrical system during new vehicle transporta-
tion and pre-delivery storage to reduce battery
depletion, while still allowing vehicle operation so
that the vehicle can be loaded, unloaded and moved
as needed by both vehicle transportation company
and dealer personnel.
The IOD fuse is disconnected from JB fuse cavity
12 when the vehicle is shipped from the assembly
plant. Dealer personnel must reconnect the IOD fuse
when the vehicle is being prepared for delivery in
order to restore full electrical system operation. Once
the vehicle is prepared for delivery, the IOD function
of this fuse becomes transparent and the fuse that
has been assigned the IOD designation becomes only
another Fused B(+) circuit fuse. The IOD fuse serves
no useful purpose to the dealer technician in the ser-
vice or diagnosis of any vehicle system or condition,
other than the same purpose as that of any other
standard circuit protection device.
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