Ignition-Off Draw Fuse Operation; Junction Block Description; Junction Block Location - Jeep 200 Cherokee Service Manual

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DESCRIPTION AND OPERATION (Continued)
sonnel are to remove the IOD fuse from the storage
location and install it into PDC fuse cavity 16 as part
of the preparation procedures performed just prior to
new vehicle delivery.
The PDC has a molded plastic cover that can be
removed to provide service access to all of the fuses
and relays in the PDC. An integral latch and hinge
tabs are molded into the PDC cover for easy removal.
A fuse layout map is integral to the underside of the
PDC cover to ensure proper fuse and relay identifica-
tion. The IOD fuse is a 15 ampere mini blade-type
fuse and, when removed, it is stored in a plastic fuse
holder formation that is molded into the underside of
the PDC cover.
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
many 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
removed is to reduce the normal IOD of the vehicle
electrical system during new vehicle transportation
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 removed from PDC fuse cavity 16
when the vehicle is shipped from the assembly plant.
Dealer personnel must install 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.
The IOD fuse can be used by the vehicle owner as
a convenient means of reducing battery depletion
when a vehicle is to be stored for periods not to
exceed about thirty days. However, it must be
remembered that removing the IOD fuse will not
eliminate IOD, but only reduce this normal condition.
If a vehicle will be stored for more than about thirty
days, the battery negative cable should be discon-
nected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals
during the vehicle storage period to prevent the bat-
tery from becoming discharged or damaged. Refer to
POWER DISTRIBUTION SYSTEMS
Battery in the index of this service manual for the
location of additional service information covering
the battery.
JUNCTION BLOCK
DESCRIPTION
Fig. 3 Junction Block Location
1 – JUNCTION BLOCK
2 – FUSE ACCESS PANEL
3 – RIGHT COWL SIDE INNER TRIM PANEL
An electrical Junction Block (JB) is concealed
behind the right cowl side inner trim panel in the
passenger compartment of the vehicle (Fig. 3). The
JB combines the functions previously provided by a
separate fuseblock module and relay center. The JB
serves to simplify and centralize numerous electrical
components, as well as to distribute electrical current
to many of the accessory systems in the vehicle. It
also eliminates the need for numerous splice connec-
tions and serves in place of a bulkhead connector
between many of the engine compartment, instru-
ment panel, and body wire harnesses. The JB houses
up to twenty-seven blade-type fuses (three standard-
type and twenty-four mini-type), up to three blade-
type automatic resetting circuit breakers, and four
International Standards Organization (ISO) relays
(three standard-type and one micro-type).
The molded plastic JB housing has integral mount-
ing brackets that are secured with three nuts to
studs on the right cowl side inner panel below the
instrument panel. The right cowl side inner trim
panel is secured to a stud on the JB with a push nut.
A snap-fit fuse access panel can be removed for ser-
vice of the JB fuses and also conceals the push nut. A
finger recess is molded into the front of the fuse
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