Locking the Seat Belt (also known as engaging the automatic locking retractor)
Almost all shoulder belts have a retractor. The retractor is the device that not only spools the excess belt, but also locks the belt so that it holds you tight in a crash.
All shoulder belts typically have an EMERGENCY locking retractor. This means that during normal driving the belt is loose – it slides freely in and out – but locks tight in an emergency, like when you slam on the brakes. During normal driving, with the shoulder belt in the emergency locking mode, you can lean forward and back, but when you slam on the brakes the shoulder belt locks and holds you tight.
If your car is a 1996 or newer, the retractor is usually a SWITCHABLE retractor – meaning that it can switch from the usual mode of locking only in an EMERGENCY, to a mode where it locks at all times – called the AUTOMATIC locking mode. Changing the belt from the EMERGENCY to AUTOMATIC locking modes is easy – simply pull the shoulder belt out all the way (do it slowly) – when you get to the very end, let the belt go back in. As it goes back in you will likely hear a ratcheting sound – and if you give a gentle pull you will notice that the belt is locked and it is not possible to make the belt any longer. In the automatic locking mode, the shoulder belt only gets shorter – it does not get longer (it will however go back to “normal” when you let the belt all the way back in).
Some cars do not have a switchable retractor. Most Jeep, Chrysler, and Dodge vehicles do not have switchable retractors – they only have the emergency locking retractor. Other vehicles that may not have a switchable retractor are some vehicles made by GM, Ford, Saab, and Volvo.