Tempo L4-122 2.0L DSL (1984)
Technical Service Bulletin # 8438
Date: 840131
Radio - System Diagnostics/Tips
Article No. 84-3-8
RADIO - SYSTEM DIAGNOSTICS - "TRICKS OF THE TRADE"
FORD ALL
LINCOLN-MERCURY ALL
LIGHT TRUCKS ALL
Product Feature Tips
Before attempting to diagnose or service a radio concern, the technician may find it helpful to take a special note of the following items, which mostly
deal with product content. This information may be helpful in resolving some customer concerns.
^
Power antennas must be fully extended (not partially) for proper operation. (Power antennas must be retracted during car wash).
^
"Up/Down" control on All-E radio is for tuning, not antenna control. (Refer to Owner's Manual for location of Antenna "Up/Down" control
switch -- Lincoln, Continental & Mark have automatic extension/retraction, when radio is turned on.
^
AM/FM bandswitch on conventional radios cannot be actuated if any station buttons are pulled out, even the slightest amount.
^
The Premium Sound boost can be turned off only with the Premium Sound switch (not on Lincoln, Mark & Continental). The Lincoln, Mark
and Continental Premium Sound option is a full-time, not switchable, system (the Premium Sound amplifier is always powered by the radio
chassis). Refer to Premium Sound section.
^
If the CB does not receive at all, be sure the squelch control is properly adjusted.
^
CB radio plays only through the front speakers (factory-installed system on Lincoln Town Car). Rear speakers are not controlled or affected
by CB operation. HELP CB system (Continental, Mark vehicles) has a self-contained speaker.
^
On All-E radios with Premium Sound option, only the front speakers are boosted.
^
Balance (Left/Right) and Fader (Front/Rear) controls:
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Balance on non-electronic cassette radio chassis is adjusted at the factory. No user adjustable control is provided.
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Front/rear fader controls are not available in 4x2 and 4x4 Trucks since they have only two (front) speakers. Tape radios in these vehicles
also have no left/right balance controls as noted above.
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Some 1983 and earlier vehicles with Premium Sound systems, having front & rear speakers amplified, have the Front/Rear Fader control
on the Premium Sound switch. Check vehicle to see if this is the case.
^
The 1984 Mustang & Capri radios are unique for the red dial lighting.
^
The 1984 Lincoln, Continental and Mark VII have the new design, replaceable mast assembly for the power antenna.
Radio Sometimes Difficult to Tune; Tuning Knob or Pushbuttons Inoperative
Tuning knob, shaft, or pushbutton may be rubbing on the trim panel. Re-position the trim panel or radio chassis to correct this condition. If trim
panel interference does not exist, the radio chassis will have to be removed and sent to an authorized service facility for service.
Poor and Noisy Reception, Ignition Noise, Missing and Faulty Noise
Poor Reception
^
If vehicle is equipped with power antenna, it must be fully extended.
^
If AM reception is extremely poor and FM reception "spits" or appears to have trouble holding stations, assure that the antenna and antenna
connectors are properly mated. If the antenna connectors are properly mated but reception is still poor, replace the antenna cable.
^
If only FM reception is poor, it is unlikely that the antenna is at fault. Remove the radio chassis for service.
NOTE:
Many customers do not understand the limitations of FM reception. Refer to Reception Characteristics for informadon about the
limitations of AM/FM radio performance.
Noise or static may result from many causes. Two of the most common sources of radio noise are listed below:
Ignition Noise
The most effective method of evaluating ignition noise is to compare the radio performance with engine on, versus engine off. If ignition noise is present
with engine running:
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Check Spark plug wires for proper routing, secure connections and continuity. (Especially the coilto-distributor wire).
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Check to see that spark plug wires are the suppresor type and that spark plugs are the correct resistor type.
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Inspect spark plugs and replace any that have cracked insulators.
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Check to see that carbon center insert in distributor cap is secure.
