1995 TOYOTA SUPRA radio

AIR CONDITIONING AMPLIFIER
AIR CONDITIONING AMPLIFIER
REMOVAL
1. REMOVE CENTER CLUSTER PANEL
(See page BO±45)
2. REMOVE RADIO WITH AIR CONDITIONING AMPLIFIER
(a) Remove the 4 screws and radio with the air conditioning
amplifier.
(b) Disconnect the connectors.
3. REMOVE AIR CONDITIONING AMPLIFIER FROM RADIO
(a) Remove the 4 screws and the 4 bolts.
(b) Remove the air conditioning amplifier from radio.
AIR CONDITIONING AMPLIFIER
INSPECTION
(See page AC±23)
AIR CONDITIONING AMPLIFIER
INSTALLATION
Installation is in the reverse order of removal.
± AIR CONDITIONING SYSTEMAIR CONDITIONING AMPLIFIERAC±109

PRECAUTION
Take care to observe the doing precautions when performing inspections or removal and replacement of
body electrical related parts.
HEADLIGHT SYSTEM
wHalogen bulbs have pressurized gas inside and require special handling. They can burst if scratched or
dropped. Hold a bulb only by its plastic or metal case.
Don't touch the glass part of a bulb with bare hands.
SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
wWork must be started after 90 seconds from the time the ignition switch is turned to the ºLOCKº position
and the negative (±) terminal cable is disconnected from the battery.
wWhen disconnecting any of the connectors in the SRS, be sure to lock the ignition switch and disconnect
the negative (±) terminal cable from the battery first. Since the connectors are twin lock type connectors,
disconnect the connectors only after releasing the first stage lock.
wWhen connecting SRS connectors, be sure to lock them securely. (If the connectors are not locked
securely, the system may not operate when needed.)
wAlways store the steering wheel pad with the pad surface facing upward. (Storing the pad with its metallic
surface up may lead to a serious accident if the SRS inflates for some reason.)
wWhen installing the spiral cable, be sure the vehicle is in the straight ahead condition and confirm that the
spiral cable is in the neutral position when it is installed.
wINFORMATION LABELS (NOTICE) are attached to the periphery of the SRS components. Follow the
NOTICE.
AUDIO SYSTEM
wIf the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 stations
stored in memory are erased, so be sure to note the stations and reset them after the battery terminal is
reconnected.
wIf the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will operate
when the cable is reconnected, but the radio, tape player and CD player will not operate. Be sure to input
the correct ID number so that the radio, tape player and CD player can be operated again.
MOBILE COMMUNICATION SYSTEM
wIf the vehicle is equipped with a mobile communication system, refer to precautions in the IN section. BE±2
± BODY ELECTRICAL SYSTEMPRECAUTION

Frequency 30 kHz 300kHz 3 MHz 30 MHz300 MHz
Designation
Modulation method
Radio wave
LF
AMFM
VHF
Amplitude modulation
HFMF
Frequency modulation
AUDIO SYSTEM
SYSTEM DESCRIPTION
1. RADIO WAVE BAND
The radio wave bands used in radio broadcasting are as follows:
LF: low Frequency MF: Medium Frequency HF: High Frequency VHF: Very High Frequency
2. SERVICE AREA
There are great differences in the size of the service area for
AM, FM monaural, and FM stereo broadcasts cannot be re-
ceived even though AM comes in very clearly.
Not only does FM stereo have the smallest service area, but
it also picks up static and other types of interference (ºnoiseº)
easily.
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±81

3. RECEPTION PROBLEMS
Besides the problem of static, there are also the problems
called ºfadingº, ºmultipathº and ºfade outº. These problems
are caused not by electrical noise but by the nature of the ra-
dio waves themselves.
Fading
Besides electrical interference, AM broadcasts are also sus-
ceptible to other types of interference, especially at night.
This is because AM radio waves bounce off the ionosphere
at night. These radio waves then interfere with the signals
from the same transmitter that reach the vehicle's antenna di-
rectly. This type of interference is called ºfadingº.
Multipath
One type of interference caused by the bouncing of radio
waves off of obstructions is called ºmultipathº. Multipath oc-
curs when a signal from the broadcast transmitter antenna
bounces off buildings and mountains and interferes with the
signal that is received directly.
Fade Out
Because FM radio waves are of higher frequencies than AM
radio waves, they bounce off buildings, mountains, and other
obstructions. For this reason, FM signals often seem to grad-
ually disappear or fade away as the vehicle goes behind a
building or other obstruction. This is called ºfade outº. BE±82
± BODY ELECTRICAL SYSTEMAUDIO SYSTEM

TROUBLESHOOTING
NOTICE: When replacing the internal mechanism (computer part) of the audio system, be careful
that no part of your body or clothing comes in contact with the terminals of the leads from the IC,
etc. of the replacement part (spare part).
HINT: This inspection procedure is a simple troubleshooting which should be carried out on the vehicle
during system operation and is based on the assumption that the cause of trouble lies with the system com-
ponents (except for the wires and connectors, etc.).
Always inspect the trouble taking the following items into consideration.
w Open or short circuit of the wire harness
w Connector or terminal connection fault
w Troubleshooting items marked *indicate that ºTroubleshooting for ANTI±THEFT SYSTEMº should be
carried out first.
 Problem No.  No power coming in. *1  Power coming in, but radio not operating. 2  Noise present, but AM±FM not operating. 3
  Either speaker does not work. 4
  Woofer speaker does not work. 5
 Radio Either AM or FM does not work. 6
  Reception poor (Volume faint). 6
  Few preset tuning bands. 6
  Sound quality poor. 7
  Cannot set station select button. 8
  Preset memory disappears. 8
  Cassette tape cannot be inserted. 9
Cassette tape inserts, but no power.*10  Power coming in, but tape player not operating. 11  Either speaker does not work. 12 Tape player Woofer speaker does not work. 13 y Sound quality poor (Volume faint). 14  Tape jammed, malfunction with tape speed or auto±reverse. 15  APS, SKIP, RPT buttons not operating. 16
  Cassette tape will not eject. *17
  CD cannot be inserted. 18
  CD inserts, but no power. 19
  Power coming in, but CD player not operating. 20
 CDplayer Sound jumps. 21
 CD player Sound quality poor (Volume faint). 22
  Either speaker does not work. 23
  Woofer speaker does not work. 24
  CD will not eject. 25
No power coming in.26 
Amplifier
 Power coming in, but woofer amplifier (Power amplifier) not operating. 27 Amplifier Either speaker does not work. 28  Woofer speaker does not work. 29
BE±86± BODY ELECTRICAL SYSTEMAUDIO SYSTEM

 Problem No.
 Noise Noise produced by vibration or shock while driving. 30
  Noise produced when engine starts. 31
 Antenna Antenna±related. 32
 ANTI±THEFT SYSTEM Troubleshooting for ANTI±THEFT SYSTEM 33
HOW TO USE DIAGNOSTIC CHART
Is tape player operating
Is ACC applied to radio?Tape player faulty.
Check if GND (wire harness side)
to radio is OK.
Radio faulty.Radio assembly faulty.
Check if CIG & RAD fuse is OK.Replace fuse.
Is ACC applied to radio?
Is ACC applied to tape player?
Is ACC applied to power amplifier?
ACC wire harness faulty?
NO POWER COMING INRadio
(1) Audio system type and symbol used.
HINT: Confirm the applicable type of audio system.
(2) Symbol for type of audio system the question applies to.
HINT: If the audio system type is not applicable, proceed to next question below.
(3) Junction without black circle.
HINT: Proceed to next question below.
(4) Junction with black circle.
HINT: Proceed to question for applicable audio system type.
(5) HINT: Select question for applicable audio system type.
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±87

1 Radio NO POWER COMING IN
Is tape player operating normally?
Is ACC applied to power amplifier?
Replace fuse.Check if RAD No. 2 fuse is OK?
Power amplifier faulty.
GND faulty.
Power amplifier faulty.
ACC wire harness faulty.Is ACC applied to radio assembly?
GND faulty.
ACC wire harness faulty.
Check if GND (wire harness side) to
radio is OK?
Radio assembly faulty.
Radio assembly faulty.
Check if GND (wire harness side)
to power amplifier is OK?
BE±88± BODY ELECTRICAL SYSTEMAUDIO SYSTEM

2 Radio POWER COMING IN, BUT RADIO NOT OPERATING
Is tape player operating normally?
Speaker wire harness faulty?
Speaker faulty?
Radio assembly faulty?
Hissing sound from speaker?
Radio assembly faulty. Recheck system after repair.
Radio assembly faulty.
Go to No. 32
Is power for the antenna
being output from the
radio or radio assembly?Radio assembly
faulty.
Is power for the antenna
being output from the
power amplifier?Power amplifier
faulty.
Is there continuity in speaker wire
harness
Temporarily install another speaker
Functions OK?
Power amplifier faulty. Recheck system
after repair.
± BODY ELECTRICAL SYSTEMAUDIO SYSTEMBE±89