Dodge Ram Truck 1500-2500-3500. Manual — part 768

REMOVAL

1. Disconnect and isolate the battery negative cable.

2. Remove cover (4) by loosening the cover screw

(1).

3. Remove the B+ terminal nut from the Integrated

Power Module (IPM) B+ terminal. Remove the B+
cable from the IPM.

4. Disconnect the gray connector from the IPM.

5. Remove the IPM retaining bolt (2) and screw (3).

6. Grasp the IPM with two hands and slide the

assembly in the direction shown to free the module
from its mounting bracket. Position the assembly
upside down to access the electrical connectors
located on the bottom of the unit.

7. Disconnect the electrical connectors by depressing

the locking tab and rotating the connector arm out-
board, until the connector is free from the IPM
assembly. Be certain to pull the connectors straight
off.

8. Remove the IPM from the vehicle.

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INSTALLATION

1. Position the Integrated Power Module (IPM) into

the vehicle.

NOTE: Integrated power module electrical connec-
tors are color coded to ease location reference.

2. Connect

the

electrical

connectors

by

pushing

straight on and rotating the connector arm inboard,
until the connector is firmly locked in place on the
IPM assembly.

3. Grasp the IPM (3) with two hands and install the

assembly onto the battery tray (2) making sure to
line up the tabs with the retaining slots in the tray
(1).

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4. Install the IPM retaining bolt (2) and screw (3).

5. Connect the gray connector on the IPM housing.

6. Install the B+ terminal cable and nut on the B+ ter-

minal.

7. Install the IPM cover (4) and tighten the retaining

screw (1).

8. Connect the battery negative cable.

IOD FUSE

DESCRIPTION

All vehicles are equipped with an Ignition-Off Draw
(IOD) fuse (1) that is disconnected within the Inte-
grated Power Module (IPM) when the vehicle is
shipped from the factory. Dealer personnel are to
reconnect the IOD fuse in the IPM as part of the new
vehicle preparation procedures and then disconnect it
again until new vehicle delivery to the customer.

A laser printed fuse layout map is integral to the IPM
cover to ensure proper fuse identification. The IOD
fuse (1) is a 20 ampere mini blade-type fuse, located
in fuse cavity # 51. The fuse is secured within a black
molded plastic fuse holder and puller unit that serves
both as a tool for disconnecting and reconnecting the
fuse in the IPM cavity, and as a fuse holder that con-
veniently stores the fuse in the same cavity after it has
been disconnected.

CIRCUITS INCLUDED WITH IOD FUSE

•

Cluster (CCN)

•

Diagnostic Connector

•

Map Lamps

•

Glove Box Lamp

•

Courtesy Lamps

•

Radio

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•

Underhood Lamp

OPERATION

The term Ignition-Off Draw (IOD) identifies a normal condition where power is being drained from the battery with
the ignition switch in the Off position. The IOD fuse feeds the memory and sleep mode functions for some of the
electronic modules in the vehicle as well as various other accessories that require battery current when the ignition
switch is in the Off position. The only reason the IOD fuse is disconnected is to reduce the normal IOD of the
vehicle electrical system during new vehicle transportation and pre-delivery storage to reduce battery depletion,
while still allowing vehicle operation so that the vehicle can be loaded, unloaded and moved as needed by both
vehicle transportation company and dealer personnel.

The IOD fuse is disconnected from Integrated Power Module (IPM) fuse cavity # 51 when the vehicle is shipped
from the assembly plant. Dealer personnel must reconnect the IOD fuse when the vehicle is being prepared for
delivery in order to restore full electrical system operation. Once the vehicle is prepared for delivery, the IOD func-
tion of this fuse becomes transparent and the fuse that has been assigned the IOD designation becomes only
another Fused B(+) circuit fuse.

The IOD fuse can be used by the vehicle owner as a convenient means of reducing battery depletion when a vehi-
cle is to be stored for periods not to exceed about thirty days. However, it must be remembered that disconnecting
the IOD fuse will not eliminate IOD, but only reduce this normal condition. If a vehicle will be stored for more than
about thirty days, the battery negative cable should be disconnected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals during the vehicle storage period to prevent the battery from
becoming discharged or damaged.

POWER OUTLET-INSTRUMENT PANEL

DESCRIPTION

A cigar lighter outlet is installed to the left of the center stack area in the lower instrument panel. The cigar lighter
outlet is secured by a snap fit within the bezel.

The cigar lighter outlet, plastic cap and the knob and heating element unit are available for service replacement.
These components cannot be repaired and, if inoperative or damaged, they must be replaced.

OPERATION

The cigar lighter consists of two major components: a knob and heating element unit, and the cigar lighter base or
outlet shell. The receptacle shell is connected to ground, and an insulated contact in the bottom of the shell is
connected to battery current. The cigar lighter receives battery voltage from a fuse in the Integrated Power Module
(IPM) when the ignition switch is in the Accessory or Run positions.

The cigar lighter knob and heating element are encased within a spring-loaded housing, which also features a slid-
ing protective heat shield. When the knob and heating element are inserted in the outlet shell, the heating element
resistor coil is grounded through its housing to the outlet shell. If the cigar lighter knob is pushed inward, the heat
shield slides up toward the knob exposing the heating element, and the heating element extends from the housing
toward the insulated contact in the bottom of the outlet shell.

Two small spring-clip retainers are located on either side of the insulated contact inside the bottom of the outlet
shell. These clips engage and hold the heating element against the insulated contact long enough for the resistor
coil to heat up. When the heating element is engaged with the contact, battery current can flow through the resistor
coil to ground, causing the resistor coil to heat.

When the resistor coil becomes sufficiently heated, excess heat radiates from the heating element causing the
spring-clips to expand. Once the spring-clips expand far enough to release the heating element, the spring-loaded
housing forces the knob and heating element to pop back outward to their relaxed position. When the cigar lighter
knob and element are pulled out of the outlet shell, the protective heat shield slides downward on the housing so
that the heating element is recessed and shielded around its circumference for safety.

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