GM Service Manual Online
For 1990-2009 cars only

Delco® System

The DELCO® entertainment system consists of an electronically tuned AM-FM stereo receiver with cassette and six speakers. The speakers are arranged as follows:

  1. The 6.5 in. front side door speakers (mid-range) mounted in the lower front doors
  2. The 2 in. front side door tweeters (high frequency) mounted to the upper front doors
  3. The 3.5 in. rear side door speakers (high/mid-range) mounted in the lower rear side doors

On the DELCO® systems, the radio performs all processing and amplification functions, and amplifies the system speakers directly.

The DELCO® radio is located in the center of the I/P and provides all operator interface to the radio and cassette (or CD changer if equipped) functions. The I/P dimmer lamp control controls the incandescent bulbs which provide the backlighting.

The park lamp input controls the LED enunciators dimming. The Vacuum Tube Fluorescent (VTF) display indicates the time of day, the radio frequency, or the CD track information. The I/P cluster supplies the Pulse Width Modulated (PWM) signal to control the VTF.

The radio internally grounds the speakers in all DELCO® music systems.

The improper installation of add-ons such as tape players, CBs, etc., may damage the system.

Delco-Bose® System

The DELCO-BOSE® entertainment system consists of the following components:

    • Electronically tuned AM-FM stereo receiver with cassette and CD (incl. mini-CD capability)
    • Speaker amplifier (mounted under the rear parcel shelf)
    • Signal processor (mounted under the rear parcel shelf)
    • 6.5 in. front side door speakers (mid-range) mounted in the lower front doors
    • 2 in. front side door tweeters (high frequency) mounted to the upper front doors
    • 3.5 in. rear side door speakers (high/mid-range) mounted in the lower rear side doors
    • 6.5 in. rear speakers (low frequency) mounted under the rear parcel shelf

On DELCO-BOSE® systems, the radio passes the line level output audio signals to the radio signal processor for processing, and then to the radio speaker amplifier for amplification to the speakers. The single amplifier powers all of the speakers.

The radio internally grounds the speakers in all DELCO-BOSE® music systems. Improper installation of add-ons such as tape players, CBs, etc., may damage the system.

The 1x24 dot matrix Vacuum Tube Fluorescent (VTF) display has the capability to show all messages in the default language of English and in French, German, Japanese Katikana and Spanish.

Backlighting for the radio is provided by incandescent lamps behind the buttons and the trimplate (PWR and VOL) inserts. The PWM signal for incandescent backlighting is supplied from the vehicle lighting center and connected directly to the lamps via pins E5 and F5 of the main connector.

When a cassette or CD is not loaded, the halo light surrounding the openings will be lit. When a cassette or CD is loaded, the halo light will extinguish.

Media Cooling

If the temperature of the cassette or the CD reaches 60° C while the radio is on, an internal cooling fan will come on to cool the cassette or CD. When the temperature has been reduced to 50° C the fan will shut off.