seatbelt question

1997 Jimmy 4X4 vinW

My seatbelts don't tighten when I am wearing them, and then pull quickly at them with my hand.

Is something wrong, or do I have the kind of seatbelt that only tightens when the car rapidly decelerates ?

How can I test if my seatbelt is working properly?

Thanks.

There are two types of retractors, your vehicle could have either one. The centrifugal style retractor should lock when you pull out rapidly on the belt, if not, they're either faulty or you have the pendulum style. The pendulum style you can check one of two ways: Raise the rear of the vehicle up about 2' and try pulling on the belt, it should not come out. Or, drive the vehicle at approximately 10MPH, apply the brakes hard and lean into the belt. The retractor should lock the belt and keep you from falling forward into the steering wheel. I have seen, more than once, when a vehicle has been undercoated, excess undercoating found its way into the retractor causing it to fail. If that's the case, you never know there's a problem until it's too late. Hope this helps.