Tempo L4-122 2.0L DSL (1984)
Typical Entertainment System Troubleshooting Tips
GENERAL INFORMATION
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Before troubleshooting a car, check for the presence and proper installation of all suppression components (capacitors and ground straps).
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When substituting components (EG. Electronic cluster and ignition system), the cause is probably in the radio system (defective radio or antenna
cable).
TAPE NOISE SYMPTOM
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Purr varying with engine RPM most noticeable at minimum volume
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Unique to cassette radio in F-Series and Bronco
SOURCE:
Power feed (37 ckt) wire routed in close proximity to the radio chassis.
CAUSE
CORRECTIVE ACTION
Magnetic Coupling to Tape
Re-route 37 cht wiring per TSB
pre-amplifier circuitry
83-7-17 procedure on customer
concern basis
AM/FM NOISE SYMPTOM
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Buzz, purr or whine varying with engine RPM, most noticeable at minimum volume with premium sound on
SOURCE:
Ignition and/or charging system
POTENTIAL CAUSE
CORRECTIVE ACTION
Ground cable on premium
Check for proper installation of
sound amplifier missing or im-
ground cable between amplifier
propely installed
and rear stud of radio (on carlines
equipped with ground cables)
Improper attachment of cables
Check attachment of battery
cables at posts and battery ground cable at engine block. Check attachment of other ground cables. Clean terminals and
mounting surfaces. Torque attaching hardware to specification.
Radio A-line fittering defective Power radio directly from separate
battery. If noise is not present, replace radio.
Low battery charge condition
Charge or replace as required.
FM NOISE SYMPTOM
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Buzzing or tone usually at discrete dial locations
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Engine Off
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Ignition switch in run or accessory position
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All motorized equipment turned off
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Noise minimized when antenna is disconnected from radio
SOURCE:
Electronic Module
POTENTIAL CAUSE
CORRECTIVE ACTION
Module radiating in band with
Remove fuses one-by-one from
sufficient energy to be de-
the fuse panel until the offend-
tected by the radio
ing power feed buss is identified
Consult the troubleshooting manual and identify modules fed from the offending power buss Disconnect these modules
one at a time until the noisy unit is isolated Install substitute module If noise occurs with key in the run position but not
in the accessory position then check the electronic engine control module by disconnecting it from vehicle wiring.
NOTE:
The ignition key should be in the off position when disconnecting or reconnecting EEC module
Defective Antenna
Perform antenna check. Replace
antenna cable is defective
AM NOISE SYMPTOM
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Hash or whine heard only with WSW, blower or cooling fan motor on.
SOURCE:
WSW, blower or cooling fan motor
POTENTIAL CAUSE
CORRECTIVE ACTION
Antenna system defective
Perform antenna system check.