Radio, Stereo, and Compact Disc: Description and Operation

The RADIO Fuse provides main voltage to the Radio. With the Ignition Switch in ACC or RUN, voltage is supplied through the RADIO Fuse and YEL wire to the On/Off Switch in the Radio. The On/Off Switch is located in the Radio (without Cassette) or Radio Control Head (with Cassette). The circuit is grounded at G202. With the On/Off Switch closed, voltage is supplied to the Solid-State Radio circuits to ground. Two wires connect each speaker to the Radio. The ETR Radio has two inputs that other models do not have: Display Dim Signal and Clock Power.

The ETR model is an AM/FM Radio that changes stations electronically. The frequency of preselected stations can be stored in the electronic memory. The ETR model also provides a digital display of time or station frequency. As in other models, the Panel Lamp Switch controls panel lamp dimming. In the ETR model, dimming is also controlled by the Radio itself by means of the Dim Display Input Signal.

The ETR model's Clock memory and Radio memory functions are supplied voltage at all times through the CTSY Fuse. If power to the ETR model is cut off - by disconnecting the Battery, for example - the operator must reset the memory functions when power is restored.

If the Cassette or Cassette/Equalizer options are included, a separate Radio Control Head is installed. This sends information along the data line to the Radio to control the volume, frequency, and other Radio functions.

REMOTE CASSETTE TAPE PLAYER (OPTIONAL)

With the Ignition Switch in ACC or RUN and the Radio Control Head ON, voltage is supplied to the Cassette Tape Player through the Radio.

With the Remote Cassette Tape Player in PLAY, the Tape Player returns a Tape ON signal and the stereo audio signals to the Radio. The Tape ON signal causes the receiver circuitry to ignore the signals from the tuner and to send the audio signals from the tape player to the speakers. With a cassette tape in FWD, REV or SEEK, the tape player applies a mute signal to the Radio to prohibit the audio sound of these functions from being heard. When the EJECT Button is pushed on the tape player, the Tape ON signal is terminated and the Radio returns to normal operation.

REMOTE GRAPHIC EQUALIZER (OPTIONAL)

With the Ignition Switch in ACC or RUN and the Radio Control Head ON, voltage is supplied to the Graphic Equalizer through the Radio Control Head. As the frequency bands are manually adjusted, this information is sent on the data line through the Radio Control Head to the Radio. The VF dim input allows dimming control of the Graphic Equalizer display when the Park or Headlamps are ON.

POWER AMPLIFIER (OPTIONAL) (SUBURBAN ONLY)

The optional power amplifier boosts the sound of the four rear speakers in the SUBURBAN when equipped with the premium sound system.

With the ignition switch in ACC or RUN position and the RADIO CONTROL HEAD ON, battery voltage is supplied to the POWER AMPLIFIER RELAY through the PNK/BLK (143) and ORN (40) wires. The relay is grounded through the BLK (150) wire at the I/P ground G202. When the relay contacts close, battery voltage is supplied to the POWER AMPLIFIER through the ORN (140) wire, the ground is completed through the BLK (150) wire at the I/P ground G202.