Steven Jay "Steve" Ames is a character from the novels Desperation and The Regulators, as well as the movie adaption of the former. Since the novels are set in seperate fictional universes, there are some notable differences between the two incarnations of Steve Ames.
Steve Ames and Cynthia Smith, as played by Steven Weber and Kelly Overton in Desperation.
Desperation
In the Stephen King novel Desperation Steven Jay Ames is working for the writer Johnny Marinville on his cross-country speaking tour. He is serving as Johnny's support crew - a step down from his previous work as a roadie for rock & roll bands. He follows Johnny to the small town of Desperation, Nevada, an event which will change both their lives. Steve is one of God's chosen. Along the way, he picks up a hitchhiking girl names Cynthia Smith, even thoug he had been forbidden from picking up Hitchhikers.
When Marinville is arrested by sherriff Collie Entragian, he is able to get a phone call through to Steve and Cynthia. The two investigate and find Johnny's motorcycle, as well as the deserted RV of the Carver family. They follow the trail to Desperation, where they eventually meet up with Marinville, David Carver, Tom Billingsley, Mary Jackson, Audrey Wyler, and Ralph Carver in the towns movie theater. Here, David reveals that it is God's will that they confront Tak, an evil being responsible for the death of everyone in Desperation, and seal it in the pit again, to which they reluctantly agree.
Eventually, Steve is one of only four people who survive the whole ordeal and leave Desperation again.
The Regulators
In the Richard Bachman novel The Regulators Steve is an easy going charming bum from New York City. His favorite saying is "No Problem Man". He studied first electrical engineering, and later general engineering, but finished neither education. He tried to make a living as a freelance guitar tech. Eventually, he managed to land a job with a club owner named Deke. When Deke purchased a new large club in San Francisco, he wanted Steve to move their stuff there in a rental truck.
On his way, Steve got in trouble when his truck blew a piston, and in an attempt to reach a garage he took a wrong turn and ended up in on Poplar Street, at the store were Cynthia Smith works. Around that same time, an ancient evil named Tak, which had been possessing an autistic boy named Seth Garin, began his grand scheme to turn Poplar Street into his own Wild West-style playground. Along with residents from the street, Steve was forced to hide in the home of Tom Billingsley to escape Tak's creations.
After severl attacks, Steve and former cop Collie Entragian attempt an escape by making their way through the greenbelt behind the houses. This plan fails when they run into a mountain lion, and Entragian is accidently killed by Jim Reeds.
After Tak is eventually defeated when Seth dies, the street returns to normal. It is implied he and Cynthia will become friends.
Adaptation
Steven Weber played Steve in the miniseries adaptation of Desperation.