1994 GMC Sonoma Owner's Manual - Page 130

Care of Your Cassette Tape Player A tapeplayer that is not cleaned regularly is subject to reduced sound quality, ruining the cassette, or adamaging the mechanism. Tape cassettes ' that are not properly stored in their plastic cases away from contaminants, direct sunlight,and extreme heat may not operate properly and could cause premature failure of the tape player. Your tape player should be cleaned monthly or with every 15 hours of use, as regular maintenance. If you notice a reduction in sound quality, trya good cassette to see if the tape or the tape player is at fault. If the second cassette resultsin no improvement in sound quality, try cleaning the tape player. Proper tape player cleaning should be done with a wiping-action non-abrasive cleaner cassette. To properly clean your tape player, you should follow the directions on the cleaning cassette. Cassettes are subject to wear and the sound quality may degrade over time. Always verify that the cassette tape is in good condition before obtaining service on your tape player.