Grand Cherokee 2WD V8-4.7L (2003)
Fuse Block: Description and Operation
Junction Block
Fig. 3 Junction Block Location
DESCRIPTION
An electrical Junction Block (JB) is concealed beneath the driver side of the instrument 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. The JB houses up to thirty-three blade-type mini fuses, up to two blade-type automatic resetting circuit breakers, the
electronic combination flasher, the Daytime Running Lamp (DRL) module (Canada only) and up to twelve International Standards Organization (ISO)
relays (three standard-type and nine micro-type). The JB also incorporates an integral connector and mounting for the Body Control Module (BCM).
The BCM is secured with four screws directly to the dash panel side of the JB. Refer to Body Control Module in Electronic Control Modules for
additional information covering the BCM.
The molded plastic JB housing has integral mounts that are secured with two screws and two snap retainers to the instrument panel steering column
support bracket behind the instrument panel steering column opening cover. The JB is concealed above the molded plastic instrument panel fuse
cover. Integral latches molded into the fuse cover secure it the JB, the BCM and the 16-way data link connector tab of the instrument panel steering
column support bracket. The fuse cover can be pulled downward to disengage the latches and provide service access to all of the fuses, relays and wire
harness connectors of the JB. The fuse cover has a fuse puller and spare fuses secured to its upper surface. Refer to Instrument Panel Fuse Cover in
Body for additional service information.
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. The BCM is available for separate service replacement.
OPERATION
