Jeep Cherokee

 Service Manual

Power distribution systems » Description and operation
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 connections and serves in place of a bulkhead connector between many of the engine compartment, instrument panel, and body wire harnesses. The JB houses up to twenty-seven blade-type fuses (three standardtype and twenty-four mini-type), up to three bladetype 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 mounting 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 service of the JB fuses and also conceals the push nut. A finger recess is molded into the front of the fuse access panel for easy removal, and a fuse puller and spare fuse holders are located on the back of the fuse access panel.

The JB unit cannot be repaired and is only serviced 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 ten wire harness connectors, which are connected to the JB through integral connector receptacles molded into the JB housing. Internal connection 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 diagrams.

Power distribution system

Power distribution center

Ignition-off draw fuse

Junction block