Radio, Stereo, and Compact Disc: Description and Operation

CIRCUIT OPERATION
The Radio receives battery voltage at all times on CKT 40 from Fuse 8 to keep clock and preset station memory alive when the Ignition is "OFF." With the Ignition Switch in "ACCY" or "RUN," RETAINED ACCESSORY POWER (RAP), voltage is applied to CKT 43 from Fuse 17 to enable Radio operation.

When the Park Lights or Headlights are turned "ON," voltage is applied to the Radio on CKT 9 from the Headlight Switch. When voltage is applied to CKT 9 at the Radio, the Radio will illuminate the display. With the Headlights or Park Lights "ON," the Radio display may be dimmed manually using the I/P Dimmer Switch. The I/P Dimmer Switch varies the voltage on CKT 8 to the Radio to control display dimming.

SPEAKERS: BASE
With the Base Speaker System, the audio signals are amplified within the Radio, and the outputs go directly to the speakers.

SPEAKERS: UW2 (10 SPEAKER SOUND SYSTEM)
For eight of the systems ten speakers, the audio signals are amplified within the Radio and the outputs go directly to the speakers.

The Amplifier is used to drive two subwoofers. The Amplifier receives all the amplified signals coming from the Radio. These signals are used to determine the Amplifier's output to the subwoofers. The Amplifier has separate power and ground inputs and is turned "ON" and "OFF" from the control output of the Radio on CKT 314.

NOISE ENTRY

FRONTWAY NOISE
Any noise which can be eliminated by unplugging the antenna from the back of the Radio.

Some Causes:
- Poor grounding of: the antenna base, the Radio or some electrical component body parts.
- Defective or marginal components: relays, solenoid, switches and electric motors. Something near the antenna coax or corrosion at antenna coax connections.

Solutions:
Always verify grounding first. If more than one component interferes, a poor ground probably exists. Pinpoint the source: suppress, shield or replace. Reroute noisy wires if necessary.

SIDEWAY NOISE
Any noise which gets quieter when the unit is slowly removed from its mounting.

Some Causes:
Noisy wires or hoses behind or on top of the Radio or antenna coax lead.

Solutions:
Suppress or shield the noisy wire or hose or reroute it. Shield the Radio case. Use aluminum or nickel tape and ground the tape whenever shielding (nickel tape will also stop magnetic interference, aluminum will not).

BACKWAY NOISE
Any noise that can be heard at minimum volume and not frontway or sideway noise.

Some Causes:
Poor grounding of the Radio or of unsuppressed electrical components. Poorly routed wires or defective suppression of electrical components.

Solutions:
Suppression can be installed at the source (preferable), the Radio or both.