what makes the front seat of a 2003 C2ntury Buick only move forward?

The horn and seat movement concerns are two different concerns and are not related in any way. The horn - you'll need to perform testing - is there power at the horn when the button is depressed? Or is it possibly a sliding contact issue in the steering wheel area causing a concern? As far as seat movement, it sounds like maybe something could be restricting movement in the other directions with the mechanism. Hands on physical testing is needed to see what is happening. www.repariapl.com/repair-shops