Power and Ground Distribution: Description and Operation

POWER DISTRIBUTION
This article covers the various standard and optional power distribution components used on this model. Refer to the Component Index of Wiring Diagrams for complete circuit diagrams of the various power distribution components.

These power distribution systems also incorporate various types of circuit control and protection features, including:
- Fuses
- Maxi-fuse cartridges
- Fusible links
- Circuit Breakers
- Relays
- Flashers
- Timers
- Circuit splice blocks.

The power distribution system for this vehicle consists of the following components:
- Power Distribution Center (PDC) located under the hood.
- Fuse Block located under the instrument panel.
- Rear Fuse/Relay Block located in the trunk area.

The power distribution system for this vehicle is designed to provide safe, reliable, centralized distribution of the electrical current required to operate all of the many standard and optional factory-installed electrical and electronic powertrain, chassis, safety, comfort and convenience systems. At the same time, these systems were designed to provide convenient to access, centralized locations for conducting diagnosis of faulty circuits, and for sourcing the additional current requirements of many aftermarket vehicle accessory and convenience items.

Following are general descriptions of the major components in the power distribution system. Refer to the vehicle owner's manual for more information on the features, use, and operation of all of the power distribution system components.

FUSE BLOCK
An electrical Fuse Block is located under the left side of the instrument panel. It serves to simplify and centralize numerous electrical components, as well as to distribute electrical current to many of the accessory systems in the vehicle.

The fuse block houses blade-type fuses, a Time Delay Relay, and the Turn Signal/Hazard Flasher. Internal connection of all the fuse block circuits is accomplished by an intricate network of hard wiring and bus bars. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

The fuses, relays, and flashers are available for service replacement. The fuse block unit cannot be repaired and is only serviced as an assembly. If any circuit or the fuse block housing is faulty or damaged, the entire fuse block and instrument panel wire harness assembly must be replaced.

FUSE/RELAY BLOCK
A Fuse/Relay block is located in the trunk and is used to provide current distribution to several electrical components. The Fuse/Relay Block has molded plastic housing that is located in the left side of the trunk. The Fuse/Relay Block has a molded plastic cover that includes an integral hinge and latch. The Fuse/Relay Block cover is easily removed for service access and has a convenient fuse and relay chart affixed to the inside surface of the cover to ensure proper component identification. The Fuse/Relay Block housing is attached to and is part of the audio amplifier mounting bracket assembly. The Fuse/Relay Block outputs are routed through the uni-body wiring harness.

A wire from the battery to the Fuse/Relay Block is used to supply current to several fuses and timer/relays located in the Fuse/Relay Block. The Fuse/Relay Block includes up to four fused and up to two timer/relays. There is one cartridge fuse, one circuit breaker, two blade type fuses, one timer/relay, and ISO one relay. Internal connection of the Fuse/Relay Block circuits is accomplished by a network of hardwired connections. The fuse cartridges, timer relays, and fuses are available for service replacement. The Fuse/Relay Block unit cannot be repaired and is only serviced as a unit with the uni-body wire harness. If the Fuse/Relay Block is faulty or damaged, the uni-body wire harness assembly must be replaced. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

NOTE: If the uni-body harness with the Fuse/Relay Block is being replaced with a new unit, be certain to transfer each of the fuses and relays from the old fuse/relay block to the proper cavities of the new fuse/relay block for proper power distribution. Refer to the fuse/relay block in Wiring Diagrams for the proper cavity assignments.

POWER DISTRIBUTION CENTER
Most of the electrical current distributed throughout this vehicle is directed through the standard equipment Power Distribution Center (PDC). The remainder of the current is directed through the rear fuse/relay block. The molded plastic PDC housing is located in the left rear corner of the engine compartment. The PDC housing has a molded plastic cover that includes an integral hinge feature, and an integral latch. The PDC cover is easily removed for service access and has a convenient fuse and relay layout label affixed to the inside surface of the cover to ensure proper component identification.

The PDC housing is secured in the engine compartment with four screws. A small molded plastic protective cover on the front end of the PDC is unsnapped to access the battery/generator cable input connection studs. All of the PDC outputs are through the integral engine compartment wire harness.

All of the current from the battery/generator cable connection enters the PDC through a 140 ampere fusible link that is secured Just inside the front end of the PDC housing. The PDC houses up to nine maxi-fuse cartridges, which replace all in-line fusible links. The PDC also houses up to ten blade-type fuses, up to four full International Standards Organization (ISO) relays, and up to eight ISO micro-relays. Internal connection of all the PDC circuits is accomplished by an intricate network of hard wiring and bus bars. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

The fuse cartridges, fuses, circuit breakers, and relays are available for service replacement. The PDC unit cannot be repaired and is only serviced as a unit with the engine compartment wire harness. If the PDC is faulty or damaged, the engine compartment wire harness assembly must be replaced.