Article 117 - Radio Noises

TSB #11 - February 11, 1972
(1972 Ford/Lincoln-Mercury - All Car Lines with Bendix AM/FM/Multiplex Radio)


The following are different types of radio noises and corrections for the AM/FM/Multiplex radio:

CONDITION: Air Conditioner Blower or Heater Blower Run-Down Noise after Ignition Turn-Off; or Excessive Hum on FM
1972 Lincoln, Thunderbird, Mark IV, Ford, Mercury, Mustang, Cougar, Torino, and Montego Cars Built Prior to October 1, 1972
    Heater or air conditioning blower motor run-down noise may be heard through the radio system for approximately 2-3 seconds after the ignition switch is turned "off" while the radio is operating. In addition, excessive hum may be heard in the radio while operating in the FM mode.

    The run-down noise can be verified by turning the radio "on" at minimum volume and turning the heater or air conditioning blower motor "on" with all other accessories "off". Turn the ignition switch "off" and listen for the run-down noise. If the noise is present, turn the radio "off" and repeat the above procedure. If the noise level does not change with the radio turned "off", the noise is not caused by the radio receiver and cannot be corrected by radio repair.

    The excessive hum can be verified by listening to the radio while playing in the FM mode with the engine running.

    CORRECTION: If any of the above noises are verified as coming from the radio, remove the radio from the vehicle and send it to an authorized Bendix Service Station.

CONDITION: Excessive Static or Background Noise when Tuned on FM Stations - All 1972 Cars with AM/FM/MPX Radios Built Prior to November 1, 1971.
    Excessive static or background noise in some radios may be present when tuned to FM stations and annoying to the owners of some subject cars.

    If the excessive static or background noise is confirmed, the vehicle should be checked to ensure that all suppression devices are properly installed and that the antenna is properly connected.

    Rotate the tone control counterclockwise to reduce the noise reception. If a tone control position can be found which effectively minimizes the noise and provides adequate radio tone response, no further action need be taken. The customer should then be instructed on use of the tone control to reduce the static and background noise.

    CORRECTION: If the tone control cannot be adjusted to minimize the noise and provide adequate tone response, the radio should be removed from the vehicle and sent to an authorized Bendix Service Station.

    NOTE: Since static and noise are problems inherent to some degree in all vehicle FM radios, customers should be referred to the 1972 AM/FM Stereo Radio Operating Manual for limitations on FM reception.

WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
TIME: Refer to the Service Labor Time Standards Manual for appropriate times.

DLR. CODING: Basic Part No. 18805 - Code 53 Article No. 118