Restraint systems (Rotary coupler): Description and operation

Rotary coupler

The rotary coupler is installed on the steering column to provide the interface between the fixed wiring harness and the moveable driver airbag module and horn buttons on the steering wheel.

A rotating link harness is encapsulated into a plastic cassette comprising outer and inner housings with integral connectors. Screws attach the outer housing to the steering column switch assembly and the inner housing is keyed to the steering wheel by its connector. The inner housing can turn a maximum of six revolutions in relation to the outer housing. For maintenance purposes the outer housing incorporates a position indicator wheel; a white tab is visible on the wheel when the rotary coupler is centralised. To prevent breaking the rotating link harness, both the steering and the rotary coupler must be centralised when removing and installing the steering wheel.

Rotary coupler components

1. Fly lead (to airbag module)
2. Outer housing
3. Position indicator wheel
4. Inner housing