A lot if times the belt and guides just need to be cleaned. in fact for my Honda they have a service bulletin on how to properly clean the belt and guide it is so common. Too many sodas and cheeseburgers make seat belts unhappy
Here is the pertinent part of the Honda service bulletin.
Cheers,
Rufus
REPAIR PROCEDURE
1. Use either isopropyl alcohol, or prepare a solution of 5 ounces of mild dishwashing
liquid in a gallon of warm water.
NOTICE
Do not use strong cleaning solutions, upholstery cleaners, or commercial
automotive interior cleaners. They can affect the durability of the webbing.
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2. Soak a clean cloth in the cleaner. Insert the cloth between the seat belt and metal
loop on the upper anchor. Use a credit card or similar item to help insert the cloth
into the loop. Work the cloth back and forth to clean the dirt out of the inside of the
loop.
3. Pull the seat belt out fully. Soak a clean cloth in the cleaner, and clean both sides of
the seat belt webbing. Dry the webbing thoroughly with a clean cloth. Do not use a
hair dryer or similar device.
4. Test the belt for proper retraction by pulling the latch plate down to the floor of the
vehicle and then releasing it. The belt should retract fully in 4 seconds or less.