Replaced Steering Rack Now Airbag Light Illuminated

I replaced the rack in my '99 Ford Taurus and like a bonehead forgot
the part in the manual about not allowing the steering wheel to rotate
while the rack was not attached to the steering knuckles on the
steering shaft (I had rotated the wheel to get the through-bolt to
line up after I got the rack all bolted up).

Anyway, now the airbag warning light flashes after startup and remains
on while the car is driven. I know something got out of whack as now
the cruise control doesn't work and neither does the horn.

What will it take to fix this problem? I have access to several same-
year cars at the local junkyard. I imagine that something in the
steering column will need to be replaced.

I feel foolish for letting this happen and my only excuse is that I
was exhausted after pulling the old rack and installing the new one.
I've been wrenching on cars for many years and I can say that pulling
the rack and replacing it was the worst job I can remember.

Any suggestions would be appreciated.

I contacted two dealers about replacing the rack and the cost was $775
from one and $800 from the other.

So what is the "clock spring" and how does one go about replacing a
broken one with a good one?

Thanks!