Component Description

AUDIO
An audio system is standard factory-installed equipment on this model, unless the vehicle is ordered with an available radio delete option. The standard equipment audio system includes an AM/FM (cassette (RAS sales code) receiver, and speakers in four locations. Several combinations of radio receivers and speaker systems are offered as optional equipment on this model. The audio system uses an ignition switched source of battery current so that the system will only operate when the ignition switch is in the ON or Accessory positions. The audio system includes the following components:
- Antenna
- Clockspring (with remote radio switches only)
- Filter, choke and speaker relay (with premium speaker system only)
- High-line or premium Central Timer Module (CTM) (with remote radio switches)
- Radio noise suppression components
- Radio receiver
- Remote radio switches (optional with RAZ radio receiver only)
- Speakers

Refer to Electrical, Restraints for more information on the clockspring. Refer to Electrical, Body Control/Central Control Module for more information on the Central Timer Module. Following are general descriptions of the remaining major components in the standard and optional factory-installed audio systems.

See the owner's manual in the vehicle glove box for more information on the features, use and operation of each of the available audio systems.

Central Timer Module
The high-line or premium Central Timer Module (CTM) can also control some features of the audio system when the vehicle is equipped with the optional RAZ radio receiver and remote radio switches. A high-line CTM is used on high-line versions of this vehicle. A premium CTM is used on vehicles equipped with the optional heated seats. The CTM combines the functions of a chime/buzzer module, an intermittent wipe module, an illuminated entry module, a remote keyless entry module, and a vehicle theft security system module in a single unit.

The high-line or premium CTM also controls and integrates many of the additional electronic functions and features included on models with this option.

The RAZ radio receiver with a remote radio switch option is one of the features that the CTM controls. The CTM is programmed to send switch status messages over the Chrysler Collision Detection (CCD) data bus to control the volume, seek, and pre-set station advance functions of the RAZ radio receiver. The CTM monitors the status of the remote radio switches located on the steering wheel through a hard wired circuit. The CTM then sends the proper switch status messages to the radio receiver. The electronic circuitry within the radio receiver responds to the switch status messages it receives by adjusting the radio settings as requested.

Refer to Electrical, Body Control/Central Timer Module for more information on the high-line CTM. Refer to Remote Radio Switch in Description and Operation for more information on this component. In addition, radio receivers connected to the CCD data bus have several audio system functions that can be diagnosed using a DRB III scan tool. Refer to the proper Diagnostic Procedures for more information on DRB III testing of the audio systems.

ANTENNA BODY & CABLE
The antenna body and cable are not readily visible in their installed positions in the vehicle. The most visible component of the antenna body and cable are the antenna adapter and the antenna cap nut, which are located on the top of the right front fender panel of the vehicle, near the right end of the cowl plenum. The antenna body and cable are secured below the fender panel by the antenna cap nut through a prefabricated and dedicated mounting hole in the top of the right front fender. The primary coaxial antenna cable is then routed beneath the fender sheet metal and through a prefabricated and dedicated cable entry hole in the right cowl side panel into the interior of the vehicle. Inside the vehicle, the primary coaxial cable is connected to a secondary instrument panel antenna coaxial cable with an in-line connector that is located behind the right end of the instrument panel. The secondary coaxial cable is then routed behind the instrument panel to the back of the radio.

The factory-installed radio antenna body and cable consists of the following components:
- Antenna adapter - The antenna adapter is sometimes also referred to as the antenna bezel or escutcheon.
- Antenna body - The die cast white metal antenna body is the mating structure between the antenna mast and the primary antenna coaxial cable.
- Antenna cable - This vehicle uses a two-piece antenna coaxial cable. The primary antenna cable is integral to the antenna body, and the secondary antenna cable connects the primary cable to the radio.
- Antenna cap nut - The antenna cap nut is a special, bright-plated threaded fastener that captures the antenna adapter and retains the antenna body to the fender sheet metal.

The components of the radio antenna body and cable cannot be adjusted or repaired. All factory-installed radios automatically compensate for radio antenna trim. Therefore, no antenna trimmer adjustment is required or possible after replacing the antenna body and cable or the radio. If an antenna body and cable component is damaged or faulty, it must be replaced. Other than the primary antenna cable, which is integral to the antenna body, the individual components of the antenna are available for service replacement.

The antenna body and cable connects the antenna mast to the radio. The radio antenna is an electromagnetic circuit component used to capture radio frequency signals that are broadcast by local commercial radio stations in both the Amplitude Modulating (AM) and Frequency Modulating (FM) frequency ranges. These electromagnetic radio frequency signals induce small electrical modulations into the antenna as they move past the mast. The antenna body transfers the weak electromagnetic radio waves induced into the rigid antenna mast into the center conductor of the flexible primary antenna coaxial cable. The braided outer shield of the antenna coaxial cable is grounded through both the antenna body and the radio chassis, effectively shielding the radio waves as they are conducted to the radio. The radio then tunes and amplifies the weak radio signals into stronger electrical signals in order to operate the audio system speakers.

The antenna body includes an integral flange that mates with and grounds the antenna body to the underside of the fender panel sheet metal. Above the fender panel, the antenna body has a short nipple that is externally threaded to accept the antenna cap nut. Inside the nipple is a plastic insulator tube, and inside this insulator is an internally threaded metal receptacle that accepts the adapter stud on the bottom of the antenna mast. The antenna adapter serves as an above fender interface to mount and secure the antenna body to the vehicle. The antenna adapter is a black molded plastic component that provides a functional transition between the top of the fender and the antenna cap nut, while concealing the edges of the antenna mounting hole and protecting the painted finish of the fender from marring as the antenna cap nut is tightened. The adapter is installed over and shrouds the threaded nipple of the antenna body, which is installed from under and protrudes through the top of the mounting hole in the fender. The antenna cap nut is installed on top of the antenna adapter and tightened onto the external threads of the antenna body nipple to effectively secure and ground the antenna body to the fender. Three notches on the outer circumference of the cap nut are engaged by matching projections of an antenna nut wrench (Special Tool C-4816) to facilitate the removal and installation of this special fastener. Proper tightening of the antenna cap nut is critical to ensuring proper grounding of the antenna body to the fender sheet metal, which is necessary for clear radio signal reception.

A short length of coaxial cable serves as the primary antenna cable. The center conductor of the cable is connected to the antenna mast receptacle. The outer wire mesh of the cable is connected to and grounded through the antenna body. One end of the primary antenna cable is securely crimped to the lower end of the antenna body, while the opposite end features a simple push/pull-type male coaxial cable connector that serves as the in-line connector to the instrument panel (secondary) antenna coaxial cable. The primary coaxial cable includes a grommet that seals the cable to an entry hole in the right cowl side outer panel where the cable passes into the passenger compartment of the vehicle. The secondary antenna cable has a push/pull-type male coaxial cable connector on the radio end, and a push/pulltype female coaxial cable connector on the opposite end, which serves as the in-line connector to the primary antenna cable. In the passenger compartment the primary cable is routed to the lower right side of the instrument panel, where it is connected to the secondary instrument panel antenna cable. The instrument panel antenna cable is routed near the instrument panel wire harness through the instrument panel to the radio and is secured to the instrument panel structural support with small metal push-on retainers. This two-piece antenna cable arrangement allows the instrument panel or the antenna body and cable to be removed or installed without disturbing the radio.

RADIO CHOKE RELAY
Models equipped with the Infinity premium speaker package have a filter, choke, and speaker relay unit. The filter, choke, and speaker relay unit is mounted to the lower instrument panel center brace, inboard of the Central Timer Module (CTM) and directly above the 16-way data link connector. The filter, choke, and speaker relay unit can be accessed for service without instrument panel disassembly or removal.

The filter, choke, and speaker relay unit should be checked if there is no sound output noted from the speakers. The filter, choke, and speaker relay unit cannot be repaired or adjusted and, if faulty or damaged, the unit must be replaced.

The filter, choke, and speaker relay unit is used to control the supply of fused battery current to the front door speaker-mounted dual amplifiers. The speaker relay is energized by a fused 12 volt output from the radio receiver whenever the radio is turned ON.

RADIO
Available factory-installed radio receivers for this model include an AM/FM/cassette (RAS sales code), an AM/FM/cassette/S-band graphic equalizer with CD changer control feature (RBN sales code), an AM/FM/ CD/3-band graphic equalizer (RBR sales code), or an AM/FM/CD/cassette/3-band graphic equalizer (RAZ sales code). The factory-installed RAZ sales code radio receivers can also communicate on the Chrysler Collision Detection (CCD) data bus network through a separate two-way wire harness connector. All factory-installed receivers are stereo Electronically Tuned Radios (ETR) and include an electronic digital clock function.

These radio receivers can only be serviced by an authorized radio repair station. See the latest Warranty Policies and Procedures for a current listing of authorized radio repair stations.

All vehicles are equipped with an Ignition-Off Draw (IOD) fuse that is removed when the vehicle is shipped from the factory. This fuse feeds various accessories that require battery current when the ignition switch is in the OFF position, including the clock. The IOD fuse is removed to prevent battery discharge during vehicle storage.

When removing or installing the IOD fuse, it is important that the ignition switch be in the OFF position. Failure to place the ignition switch in the OFF position can cause the radio display to become scrambled when the IOD fuse is removed and replaced. Removing and replacing the IOD fuse again, with the ignition switch in the OFF position, will correct the scrambled display condition.

The IOD fuse should be checked if the radio or clock displays are inoperative. The IOD fuse is located in the junction block. Refer to the fuse layout label on the back of the instrument panel fuse access panel for IOD fuse identification and location.

The radio receiver operates on fused battery current that is available only when the ignition switch is in the ON or Accessory positions. The electronic digital clock function of the radio operates on fused battery current supplied through the IOD fuse, regardless of the ignition switch position.

For more information on the features, setting procedures, and control functions for each of the available factory-installed radio receivers, see the owner's manual in the vehicle glove box.

RADIO NOISE SUPPRESSION COMPONENTS
Radio Frequency Interference (RFI) and Electro Magnetic Interference (EMI) noise suppression is accomplished primarily through circuitry internal to the radio receivers. These internal suppression devices are only serviced as part of the radio receiver.

External suppression devices that are used on this vehicle to control RFI or EMI noise include the following:
- Radio antenna base ground
- Radio receiver chassis ground wire or strap Engine-to-body ground straps
- Cab-to-bed ground strap Heater core ground strap
- Resistor-type spark plugs
- Radio suppression-type secondary ignition wiring.

For more information on the spark plugs and secondary ignition components, refer to Electrical, Ignition Control.

REMOTE SWITCHES
A remote radio switch option is available on models equipped with the AM/FM/CD/cassette/3-band graphic equalizer (RAZ sales code) radio receiver and the high-line Central Timer Module (CTM). Refer to Electrical, Body Control/Central Timer Module for more information on this component.

Fig.15 Remote Radio Switches:

Two rocker-type switches are mounted in the sides of the rear (instrument panel side) steering wheel trim cover. The switch on the left side is the seek switch and has seek up, seek down, and preset station advance functions. The switch on the right side is the volume control switch and has volume up, and volume down functions. The two switches are retained in mounting holes located on each side of the rear steering wheel trim cover by four latches that are integral to the switches.

The remote radio switches share a common steering wheel wire harness with the vehicle speed control switches. The steering wheel wire harness is connected to the instrument panel wire harness through the clockspring. Refer to Electrical, Clockspring for more information on this component.

The remote radio switches are resistor multiplexed units that are hard wired to the high-line or premium CTM through the clockspring. The CTM monitors the status of the remote radio switches and sends the proper switch status messages on the Chrysler Collision Detection (CCD) data bus network to the radio receiver. The electronic circuitry within the radio is programmed to respond to these remote radio switch status messages by adjusting the radio settings as requested.

For diagnosis of the CTM or the CCD data bus, the use of a DRB III scan tool and the proper Diagnostic Procedures are recommended. For more information on the features and control functions for each of the remote radio switches, see the owner's manual in the vehicle glove box.

SPEAKERS
Standard
The standard equipment speaker system includes speakers in four locations. One full-range 15.2 by 22.9 centimeter (6.0 by 9.0 inch) speaker is located in each front door. There is also one full-range 13.3 centimeter (5.25 inch) diameter speaker located in each rear cab side panel for the standard cab and the club cab models, or in each rear door of the quad cab models.

Each of the four full-range speakers used in the standard speaker system is driven by the amplifier that is integral to the factory-installed radio receiver.

Premium
The optional premium speaker system features Infinity model speakers in six locations. Each of the standard front door speakers are replaced with Infinity model speakers that include integral dual 30 watt amplifiers. Each of the standard rear speakers is also replaced by an Infinity model speaker. The premium speaker system also includes an additional Infinity tweeter mounted in the A-pillar garnish molding. The total available power of the premium speaker system is about 120 watts.

The Infinity speakers used in the premium speaker system are driven by dual amplifiers that are integral to each of the front door speakers. One of these dual amplifiers drives the front door speaker and the A-pillar mounted tweeter for that side of the vehicle, while the other amplifier drives the rear speaker for that side of the vehicle.