Fuse Block: Description and Operation

DESCRIPTION
Junction Block

Junction Block:

An electrical Junction Block (JB) is concealed behind the left outboard end of the instrument panel cover. The molded plastic JB housing has integral mounting 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 junction block fuses. 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 label to ensure proper fuse identification.

The JB combines the functions previously provided by a separate fuseblock module and relay center, serves to simplify and centralize numerous electrical components, and 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.

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. The JB houses up to nineteen blade-type fuses (two standard-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). Internal connection of all of the JB circuits is accomplished by an intricate combination of hard wiring and bus bars.

The fuses, circuit breakers, and relays are available for service replacement. The JB unit cannot be repaired and is only serviced as an assembly. If any internal circuit or if the JB housing is faulty or damaged, the entire JB unit must be replaced.

Relay And Fuse Block
An additional relay and fuse block is used on this model. The relay and fuse block is snap fit onto mounting tabs located on the end of the Junction Block (JB) nearest to the dash panel, under the left outboard end of the instrument panel. The relay and fuse block provides additional capacity for distribution and control of electrical current for some of the accessory systems that are unique to this vehicle, and which could not be accommodated by the Junction Block (JB) or the Power Distribution Center (PDC).

Relay And Fuse Block:

The relay and fuse block components are accessed for service by removing the steering column opening cover from the instrument panel. The relay and fuse block is then disengaged from the JB mounting tabs and pulled out from under the instrument panel. Service replacement of the relay and fuse block unit requires instrument panel assembly removal.

The relay and fuse block is integral to the instrument panel wire harness, and all circuits entering or leaving this module do so through the instrument panel wire harness. The relay and fuse block has cavities for up to four additional blade-type mini fuses, the electronic combination flasher, and three additional International Standards Organization relays (one standard-type and two micro-type). Internal connection of all of the relay and fuse block circuits is accomplished by hard wiring.

The fuses, flasher and relays are available for service replacement. The relay and fuse block unit cannot be repaired and is only serviced as a unit with the instrument panel wire harness assembly. If the relay and fuse block housing or its internal circuits are faulty or damaged, the entire instrument panel wire harness unit must be replaced.