Ford Ranger Owner's Manual page 151

Push the k button to activate Dolby B Noise Reduction. Push
again to deactivate.
Tips on Caring for the Cassette Player and Tapes
In order to keep your cassette tape player performing the way it
was meant to, read and follow these simple precautions:
Using a Ford Cassette Cleaning Cartridge to clean the tape
player head after 10-12 hours of play will help maintain the
best playback sound and proper tape operation.
Only cassettes that are 90 minutes long or less should be
used. Tapes longer than 90 minutes are thinner and subject
to breakage or may jam the tape player mechanism.
Protect cassettes from exposure to direct sunlight, high
humidity and extreme heat or cold. If they are exposed to
extreme conditions, allow them to reach a moderate
temperature before playing.
If a tape is loose inside the cassette, tighten it before playing
by putting your finger or a pencil into one of the holes and
turning the hub until the tape is tight.
Loose labels on cassette tapes can become lodged in the
mechanism. Remove any loose label material before inserting
cassette.
Do not leave a tape in the cassette tape player. High heat in
the vehicle can cause the cassette to warp.
Clock Operation
How to view the clock mode
Press the "CLK" button to display time. The time will continue
to be displayed until a radio or tape function is chosen. After
approximately 10 seconds, the time will again appear in the
display. To display radio or tape information only, press the
"CLK" button a second time.
Electronic Sound Systems
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