Audio Systems: 92 Ford Taraus tuner constantly drifts, ford taraus, copper foil

Question
Recently the tuner on my factory installed AM/FM cassette radio stopped being able to "hold" a tuned frequency on both AM/FM bands.

In other words, it will scan/seek w/o stopping, and if manually tuned to a frequency, the station broadcasting on that frequency will not be heard.  HOWEVER, if manually tuned to a station, often one will then hear stations "coming and going", AS IF there were a manual tuning knob and someone were turning it very slowly (once audible, a station will be heard for about 5-10 seconds before it fades out again) in the direction of higher frequencies to lower frequencies.  During this time, the frequency display on the LCD does not change (though the STereo indicator will come on and go off as stations come and go).

Any recommendations on how to deal with this are welcome!  

Answer
Michael,
The problem that you are describing is due to a fault with the automatic fine tuning section (AFT) The AFT is causing the tune voltage to continue to run past the lock point. On many stereos with this problem I find that the AFT feedback voltage is missing due to a shorted capacitor or a leaky capacitor that corroded a copper foil trace on the circuit board.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net