Audio: Overview Dodge Pickup R2500

DESCRIPTION

An audio system is standard factory-installed equipment on this model. Several combinations of radio receivers and speaker systems are offered. 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 RUN or ACCESSORY positions.

The audio system includes the following components

1. Antenna
2. Power amplifier (with premium speaker system only)
3. Radio noise suppression components
4. Radio receiver
5. Remote radio switches (if equipped)
6. Speakers

Certain functions and features of the audio system rely upon resources shared with other electronic modules in the vehicle over the Programmable Communication Interface (PCI) bus network. The data bus network allows the sharing of sensor information. For diagnosis of these electronic modules or of the data bus network, the use of a DRB III(R) scan tool and the proper Diagnostic Procedures are recommended.

Refer to SYSTEM WIRING DIAGRAMS - R1500 , SYSTEM WIRING DIAGRAMS - R2500 or SYSTEM WIRING DIAGRAMS - R3500 for complete standard and premium audio system circuit diagrams. The wiring information includes 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.

OPERATION

The audio system components are designed to provide audio entertainment and information through the reception, tuning and amplification of locally broadcast radio signals in both the Amplitude Modulating (AM) and Frequency Modulating (FM) commercial frequency ranges.

The audio system components operate on battery current received through a fuse in the Integrated Power Module (IPM) on a fused ignition switch output (run-acc) circuit so that the system will only operate when the ignition switch is in the Run or Accessory positions.

On vehicles that are equipped with the optional remote radio switches, the Instrument Cluster receives hard wired resistor multiplexed inputs from the remote radio switches. The programming in the Instrument Cluster allows it to process those inputs and send the proper messages to the radio receiver over the Programmable Communication Interface (PCI) bus network to control the radio volume up or down, station seek up or down, preset station advance, and mode advance functions.

Refer to the owner's manual for more information on the features, use and operation of each of the available audio systems.

Any diagnosis of the Audio system should begin with the use of the DRB III(R) diagnostic tool. For information on the use of the DRB III(R), refer to ELECTRONIC CONTROL MODULES .

Refer to SYSTEM WIRING DIAGRAMS - R1500 , SYSTEM WIRING DIAGRAMS - R2500 or SYSTEM WIRING DIAGRAMS - R3500 . The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

Scheme 1

Scheme 2

The optional Infinity premium speaker system includes a separate Infinity audio power amplifier. The amplifier is a six channel unit and is rated at 240 total output watts. The amplifier is located behind the glove box.

The power amplifier electronically increases the frequency response of the normal audio signal output from the radio amplifier in order to improve the acoustic performance of the speakers. On vehicles equipped with an amplifier, the amplifier section of the radio becomes a pre-amplifier.

The amplifier receives audio signal inputs for speaker channels from the radio, then sends amplified audio outputs through six separate channels with dedicated feed and return circuits to the individual speakers.

Scheme 3

1. Disconnect and isolate the battery negative cable.
2. Remove glove box (Refer to «REMOVAL»(/dodge/pickup-r2500/1996-2010/remont/gauges-instrument-panels/#instrument-panel) ).
3. Remove instrument panel center bezel (Refer to «REMOVAL»(/dodge/pickup-r2500/1996-2010/remont/gauges-instrument-panels/#instrument-panel) ).
4. Remove instrument panel lower right center bezel (Refer to «REMOVAL»(/dodge/pickup-r2500/1996-2010/remont/gauges-instrument-panels/#instrument-panel) ).
5. Disconnect electrical harness connector from amplifier (Scheme 3)
6. Remove mounting bolts.

The antenna body and cable is secured below the fender panel by the antenna cap nut through a mounting hole in the right front fender. The primary coaxial antenna cable is then routed beneath the fender sheet metal and through a 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 kick panel. The secondary coaxial cable is then routed behind the instrument panel to the back of the radio.

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.

Available factory-installed radio receivers for this model include

1. AM/FM/cassette with CD changer control feature (RBB sales code)
2. AM/FM/cassette/CD/graphic equalizer with CD changer control feature (RAZ sales code)
3. AM/FM/CD with CD changer control feature (RBK sales code)
4. AM/FM/CD with 6 CD changer (RBQ sales code)
5. AM/FM/cassette/CD (RBY sales code) - export only

All factory-installed radio receivers can communicate on the Programmable Communications Interface (PCI) data bus network. 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 manual for a current listing of authorized radio repair stations.

The radio receiver operates on ignition switched 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, refer to the owner's manual.

Scheme 4

1. Disconnect and isolate the battery negative cable.
2. Remove center instrument panel bezel (Refer to «REMOVAL»(/dodge/pickup-r2500/1996-2010/remont/gauges-instrument-panels/#instrument-panel) ).
3. Remove radio mounting screws (Scheme 4)
4. Disconnect electrical harness connector. CAUTION: Pulling the antenna cable straight out of the radio without pulling on the locking antenna connector could damage the cable or radio.
5. Disconnect the antenna cable by pulling the locking antenna connector away from the radio (Scheme 5)

Scheme 5

Radio noise suppression devices are factory-in-stalled standard equipment on this vehicle. Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) can be produced by any on-board or external source of electromagnetic energy. These electromagnetic energy sources can radiate electromagnetic signals through the air, or conduct them through the vehicle electrical system.

When the audio system converts RFI or EMI to an audible acoustic wave form, it is referred to as radio noise. This undesirable radio noise is generally manifested in the form of "buzzing," "hissing," "popping," "clicking," "crackling," and/or "whirring" sounds. In most cases, RFI and EMI radio noise can be suppressed using a combination of vehicle and component grounding, filtering and shielding techniques. This vehicle is equipped with factory-installed radio noise suppression devices that were designed to minimize exposure to typical sources of RFI and EMI; thereby, minimizing radio noise complaints.

Factory-installed radio noise suppression is accomplished primarily through circuitry or devices that are integral to the factory-installed radios, audio power amplifiers and other on-board electrical components such as generators, wiper motors, blower motors, and fuel pumps that have been found to be potential sources of RFI or EMI. External radio noise suppression devices that are used on this vehicle to control RFI or EMI, and can be serviced, include the following

1. Engine-to-body ground strap - This length of braided ground strap has an eyelet terminal connector crimped to each end. One end is secured to the engine cylinder head(s). The other is secured to the plenum at the exhaust heat shield forward/outer attaching stud.
2. Resistor-type spark plugs - This type of spark plug has an internal resistor connected in series between the spark plug terminal and the center electrode to help reduce the production of electromagnetic radiation that can result in radio noise.

There are two common strategies that can be used to suppress Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) radio noise. The first suppression strategy involves preventing the production of RFI and EMI electromagnetic signals at their sources. The second suppression strategy involves preventing the reception of RFI and EMI electromagnetic signals by the audio system components.

The use of braided ground straps in key locations is part of the RFI and EMI prevention strategy. These ground straps ensure adequate ground paths, particularly for high current components such as many of those found in the starting, charging, ignition, engine control and transmission control systems. An insufficient ground path for any of these high current components may result in radio noise caused by induced voltages created as the high current seeks alternative ground paths through components or circuits intended for use by, or in close proximity to the audio system components or circuits.

Preventing the reception of RFI and EMI is accomplished by ensuring that the audio system components are correctly installed in the vehicle. Loose, corroded or improperly soldered wire harness connections, improperly routed wiring and inadequate audio system component grounding can all contribute to the reception of RFI and EMI. A properly grounded antenna body and radio chassis, as well as a shielded antenna coaxial cable with clean and tight connections will each help reduce the potential for reception of RFI and EMI.

Scheme 6

1. Disconnect and isolate the battery negative cable.
2. Remove the attaching bolts and strap (Scheme 6)

Scheme 7

Scheme 8

1. Disconnect and isolate the battery negative cable.
2. Remove the attaching bolts from the cylinder heads (Scheme 7)
3. Remove nut from heat shield and remove strap (Scheme 8)

Scheme 9

1. Disconnect and isolate the battery negative cable.
2. Remove the attaching bolts from the cylinder heads (Scheme 9)
3. Remove nut from heat shield and remove strap (Scheme 8)

A remote radio control switch option is available on some models. Two rocker-type switches are mounted on the back (instrument panel side) of the steering wheel spokes (Scheme 10) The switch on the left spoke is the seek switch and has seek up, seek down, and preset station advance functions. The switch on the right spoke is the volume control switch and has volume up, and volume down functions. The switch on the right spoke also includes a "mode" control that allows the driver to sequentially select AM radio, FM radio, cassette player, CD player or CD changer (if equipped).

Scheme 10

The six switches in the two remote radio switch units are normally open, resistor multiplexed momentary switches that are hard wired to the Integrated Power Module (IPM) through the clockspring. The IPM sends a five volt reference signal to both switch units on one circuit, and senses the status of all of the switches by reading the voltage drop on a second circuit.

When the IPM senses an input (voltage drop) from any one of the remote radio switches, it sends the proper switch status messages on the Programmable Communication Interface (PCI) data bus network to the radio receiver. The electronic circuitry within the radio receiver is programmed to respond to these remote radio switch status messages by adjusting the radio settings as requested. For diagnosis of the IPM or the PCI data bus, the use of a DRB III(R) 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, refer to the owner's manual.

Two wires connected to each speaker, one feed circuit (+) and one return circuit (-), allow the audio output signal electrical current to flow through the voice coil. For complete circuit diagrams, refer to SYSTEM WIRING DIAGRAMS - R1500 , SYSTEM WIRING DIAGRAMS - R2500 or SYSTEM WIRING DIAGRAMS - R3500 . The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

See also:
• REMOVAL