I have an 89 Ford F-250 with a stock receiver and if you have a casette in and you hit the brakes the radio makes a very annoying buzzing noise. It dosent do this when the am or fm radio is on, just when the a casette is playing. I have another problem also. Whenever playing music, most times my right door speaker rattles and makes a distorted vibrating sound. I know this is normal for a 20+ year old truck but is there anything i can do to fix these problems?
Your door rattles? the stock speaker could possibly be loose and the sound vibrations could be making it vibrate back and fourth. Another possible cause is the speaker is a P.O.S. and is blown. If I were you Id just replace both the head unit, and the speakers with nice aftermarket ones. Fairly cheap, and easy to install.