The early '90s to '96 model Ford cassette radio is one of two models that can not be repaired. Don't even waste your money on one from a salvage yard. This is the only time I recommend an aftermarket replacement over a factory-original radio.
The display issue is caused by a burned out back lighting bulb. All older mechanics are familiar with replacing those. You pop the top cover off, twist the lamp socket and pull it out, then slide in a new bulb. Get a bulb from the dealer. It is a frosted bulb to disperse the light evenly. A Chrysler dash board light or back lighting bulb for their headlight switches and heater controls will fit but those are clear and will cause the center of the display to be brighter than the edges.
The problem with these radios is the copper on the printed circuit boards deteriorates and crumbles off. The list of symptoms is almost endless. Yours depends on which copper circuit breaks apart first. Even when you try to swap complete circuit boards between multiple radios, you'll end up with many more problems than what you started with because the vibration and flexing cause the copper to crumble on more circuits. I tried to make one good radio out of six. One had no sound on the left channel. One had no FM. One had no reception at all. By the time I gave up, none of the radios had their one original problem. Even if you contact the grossly over-priced factory-authorized repair centers, they will tell you these radios can't be fixed, or that "parts are no longer available".
Wednesday, September 24th, 2014 AT 7:46 PM