Really? You never heard of the clock spring in the steering column, you must be working on da BIG trucks judging by your user name. A clock spring is the assembly in the steering column just under the steering wheel that the circuitry for the airbag, horn and cruise control buttons run through. Its purpose is to allow for electrical contact from the air bag, horn and cruise control buttons on the steering wheel to the wiring in the column. It's REAL common for one of the circuits in this "clock spring" as it's called, to break over time and then your cruise control, horn or airbag may not function properly. I hope this helps tonkadoctor....if you need more info a search on google will turn up days worth of reading material about clock springs in vehicles.