robbynne

As promised, albeit a bit late, are the details of my repair of the PDC (Power Distribution Center).
This post is comprised of two (2) parts due to the size restriction of 15,000 character per post.

PART 1

Terminology-
Before I begin it makes sense to define some of the acronyms used in this article.

IPM - Integrated Power Module. The IPM consists of the PDC (Power Distribution Center) and the FCM (Front Control Module).

PDC - Power Distribution Center. The PDC is a printed circuit board (PCB) based module which contains fuses, relays, overcurrent protection devices and the metal buss bars required for voltage distribution and protection for the entire vehicle.

FCM - Front Control Module. The FCM is a microcomputer based module in a silver metal housing attached to the PDC. The FCM controls power to some of the vehicles electrical systems based on input from hard wired switches and data received on the PCI bus.

PCI - Programmable Communications Interface. A data communication bus network over which the FCM receives and transmits data.

PCB - Printed Circuit Board. A glass epoxy board (most commonly green in color) on which copper circuits are etched and electronic components are mounted via solder connections. There is a PCB in the PDC as well as the FCM.

DRSM - Dodge Ram Service Manual. A factory service manual.

Useful Tools and Implements-

Phillips head screwdriver
13mm open end wrench
13mm socket attached to ratchet wrench
Hex driver (1/4")
Anti static discharge wrist band (optional)
Small, flat, thin bladed screwdriver (approximately 1/8" wide tip)
Stiff narrow plastic putty knife or spatula
Popsicle sticks (aka, craft sticks @ Walmart)
Tongue depressors (aka, jumbo craft sticks @ Walmart)
Toothpicks
Cotton swabs (aka, Q-Tips)
Aerosol spray electrical contact cleaner
Compressed air
Aerosol spray dry silicone lubricant
Metallic ink Sharpie permanent marker (preferably silver)
Small diameter drill bits ( 3/32" and 1/8")
Dremel rotary tool with #194 High Speed Cutter
Soldering iron with 800-900 degree tip
Electronic solder (rosin core, NOT ACID core)
Braided solder wick
Solder sucker
Three #6 x 1/2" or #8 x 1/2" stainless steel sheet metal screws
Silicone sealant (clear)
Soft brushes (e.g., toothbrush, small disposable paint brush)
Paper and pencil for making notes/sketches
Digital camera (in lieu of paper and pencil)
Patience, caution and a light touch....



1. Disconnect the negative and positive battery cables (13mm open end wrench) (per DRSM 8W-97-3).

2. Unsnap the cover and remove the B+ terminal nut (13 mm) from the IPM. Remove the B+ cable.

3. Remove the gray connector from the PDC housing (it is secured by a push-fit barbed plastic connector). It is not necessary to undo the gray connector itself.

4. Remove the IPM retaining bolt (13 mm) and the plastic Phillips head screw.

5. Grasp the IPM with two hands and slide the assembly horizontally toward the passenger side of the vehicle. It should move approximately 3/4"; do NOT pry against the flat metal assembly (Front Control Module) near the fender wall. The IPM is secured to the battery tray by two (2) plastic stubs which engage slotted keyways in the battery tray (Fig. 5 DRSM 8W-97-5). Once the IPM has been slid to the left, gently pull the assembly toward the front of the vehicle to disengage the tabs from the battery tray keyways.

6. Rotate the assembly counter clockwise until it is upside down to access the seven (7) color coded electrical connectors. The five (5) larger connectors are removed by disengaging the locking tab and rotating the connector arm. Be careful not to break the connector arm. The connectors are generally dusty and sometimes do not move freely. It helps to wiggle the connectors slightly as you pull them straight off. I used a bit of silicone dry lube spray at the pivot points to aid in removal. The two (2) smaller electrical connectors are removed by disengaging the locking tab and pulling them straight off. The five (5) larger connectors are color coded (gray, white, black, blue, green) so it is not necessary to label them unless you are color blind. The two (2) smaller connectors are color coded (black and green) as well. Once all the electrical connectors have been released, remove the IPM assembly.

7. Place the IPM assembly on a bench and remove the four (4) screws holding the Front Control Module (flat silver metal assembly) in place. The FCM is a solid state device so I took the precaution of using a grounding wrist band when touching the module. If you do not have a grounding wrist band simply be sure and touch a grounded metal object (NOT the FCM) to discharge any static charge you may have acquired BEFORE you touch the FCM.

8. Remove the FCM by pulling it straight off the IPM assembly.