Radio/Stereo: Description and Operation

AUDIO SYSTEM
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 [1][2]remote radio switches only)
- High-line Central Timer Module (CTM) (with [1][2]remote radio switches)
- Power amplifier (with premium speaker system only)
- Radio noise suppression components
- Radio receiver
- [1][2]Remote radio switches (optional with RAZ radio receiver only)
- Speakers

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 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 [1][2]remote radio switches. A high-line CTM is used on high-line versions of this vehicle. 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 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 [1][2]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 [1][2]Remote Radio Switch 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 scan tool.

RADIO RECEIVER
Available factory-installed radio receivers for this model include an AM/FM/cassette (RAS sales code), an AM/FM/cassette/5-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.

IGNITION-OFF DRAW FUSE
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.

[1][2]REMOTE RADIO SWITCH
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).

Remote Radio Switch:

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 [1][2]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.

The [1][2]remote radio switches are resistor multiplexed units that are hard wired to the high-line 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 scan tool and the proper Diagnostic Procedures are recommended. For more information on the features and control functions for each of the [1][2]remote radio switches, see the owner's manual in the vehicle glove box.

SPEAKER SYSTEM
Standard
The standard equipment speaker system includes speakers in four locations. One full-range 16.5 centimeter (6.5 inch) diameter speaker is located in each front door. There is also one full-range 16.5 centimeter (6.5 inch) diameter speaker located in each rear door.

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 eight Infinity model speakers in six locations. Each of the standard speakers in the front doors is replaced with Infinity model speakers, and an additional 6.9 centimeter (2.75 inch) diameter Infinity dome tweeter is mounted high in the front door trim panels. The standard speakers in the rear doors are each replaced with an Infinity 16.5 centimeter (6.5 inch) diameter coaxial unit. The premium speaker system also includes an additional Infinity power amplifier. The total available power of the premium speaker system is about 100 watts.

The eight Infinity speakers used in the premium speaker system are all driven by the radio receiver through an Infinity power amplifier.

POWER AMPLIFIER
Models equipped with the Infinity premium speaker package have a separate power amplifier unit. This power amplifier is rated at 100 watts output. The power amplifier unit is mounted to the right cowl side inner panel under the passenger side end of the instrument panel. The power amplifier unit can be accessed for service by removing the trim from the right cowl side inner panel.

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

The power amplifier receives fused battery current from a fuse in the Junction Block (JB) at all times. The internal circuitry of the power amplifier switches the amplifier on based upon a fused 12 volt output signal that is received from the radio receiver whenever the radio is turned on. The power amplifier receives the sound signal inputs for four speaker channels from the radio receiver, then sends the amplified speaker outputs for each of those channels to the eight speakers.

ANTENNA
All models use a black painted fixed-length stainless steel rod-type antenna mast, installed on the right front fender of the vehicle. The antenna mast has a spiral groove cut down its length to reduce wind noise. The antenna mast is connected to the center wire of the coaxial antenna cable, and is not grounded to any part of the vehicle. To eliminate static, the antenna base must have a good ground. The coaxial antenna cable shield (the outer wire mesh of the cable) is grounded to the antenna base and the radio receiver chassis.

The antenna coaxial cable has an additional disconnect, located near the inboard side of the glove box opening on the back side of the lower instrument panel reinforcement. This additional disconnect allows the instrument panel assembly to be removed and installed without removing the radio receiver.

The factory-installed Electronically Tuned Radios (ETR) automatically compensate for radio antenna trim. Therefore, no antenna trimmer adjustment is required or possible when replacing the radio receiver or the antenna.

RADIO NOISE SUPPRESSION
Radio Frequency Interference (RFI) and Electromagnetic 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 strap(s)
- Exhaust system-to-body ground strap (4.7L engines only)
- Resistor-type spark plugs
- Radio suppression-type secondary ignition wiring.