Workshop Manuals Factory service & repair Land Rover
01 Introduction02 Multiport fuel injection (MFI-V8)03 Multiport fuel injection (MFI-T16)04 300Tdi05 300Tdi glow plug control06 Starting and charging07 Cruise control08 Ignition and shift interlock09 Anti-lock brake system10 Data link connector11 Instruments12 Warnings and indicators13 Horns14 Radio (EXCEPT Japan)15 Radio (Japan)16 Radio (NAS)17 Front wipe/wash18 Rear wipe/wash19 Heated front screen20 Heated rear screen and mirror demisters21 Electrochromic rear view mirror22 Multi-function unit (MFU)23 Headlamps (EXCEPT Japan)24 Headlamps (Japan)25 Headlamp levelling26 Side lamps27 Stop lamps28 Direction indicator lamps29 Reversing lamps30 Fog guard lamps31 Interior lamps32 Cigar lighter/clock33 Blower controls34 Compressor controls35 Cooling fans36 Power windows37 Sunroof38 Central locking (EXCEPT Japan)39 Central locking (Japan)40 Power seats41 Power mirrors42 Trailer auxiliary socket43 Theft alarm system44 Power distribution45 Fuse details46 Ground distribution47 Component location table48 Component location views49 Connector views50 Harness routing
Land Rover Discovery Electrical Troubleshooting Manual (1997 on)14 · Radio (EXCEPT Japan)
14 · Electrical

Radio (except Japan) – circuit operation

Make
Land Rover
Model
Discovery Electrical Troubleshooting Manual
Year
1997 on
Section
Circuit operation › Radio (except Japan) – circuit operation
Radio (EXCEPT Japan)Radio (except Japan) – circuit operation

RADIO (EXCEPT JAPAN) – CIRCUIT OPERATION

CIRCUIT OPERATION

The audio system consists of a new head unit, and for mid/high- range, a subwoofer and subwoofer amplifier. For mid- and high-range, the system is also equipped with a radio waveband switch and a tune switch, a volume up and a volume down switch which are located on the fascia next to the instrument cluster. The control head is equipped with an anti-theft feature which makes the unit inoperative once battery power is removed. A security code must be entered to restore power to the unit. On every level the system is equipped with two rear and two front speakers. Optional front tweeters are available for high line radio. Battery voltage is provided to the control head at all times through the P wire. In addition to monitoring the anti-theft feature, this input keeps the preset station memory alive. Whenever battery power to the unit is lost, the anti-theft code must be entered and the preset stations must be reprogrammed. When the Radio (Z111) and the ignition are turned on, the voltage signal through the LGO wire and the control head  wakes up  the unit. The Radio (Z111) plays, the VF display comes on, and the control unit buttons illuminate. The VF display is dimmed when the headlights or park lights are turned on. When the lights are on, voltage from fuse F8 of the Fascia Fusebox (P126) is applied to the Radio (Z111) terminal 6, connector 230 signalling the Radio (Z111) to dim the display.

Side Screen Antenna

The antenna is now printed into the rear side screen on four door models. For America and Japan the element is fitted in both rear side screens, known as diversity antenna system. Other markets have a single element in the right hand side screen only. Diversity reception means that if vehicle movement results in a loss of signal due to reflections from buildings (known as multipath distortion), the radio will switch to the antenna receiving the strongest signal. This results in less interference and better stereo performance.

Antenna Amplifier

New antenna amplifiers are located behind the headlining above the side screen antenna(s). Right

hand side fitment is an FM + AM amplifier, left hand side, diversity, is an FM only amplifier.

Subwoofer

The subwoofer unit is located in the right hand side of the luggage compartment. It amplifies frequencies between 20 and 150 Hz to give an enhanced bass sound.

Subwoofer Amplifier

The amplifier is fitted on top of the subwoofer unit.

Parts & tools for this job For 1997 Land Rover Discovery

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