93 ford aerostar airbag code 13

i have a 93 ford aerostar with a 3.0
i am getting a code 13 with the air bag light
flash once then 3 times over and over just started
lately the horn started going off for no reason had to unplug it to make it stop any guess on this

also on the 93 is there a tool to pull the codes or does it need to be taken in to a shop ?

i am pretty good at repairs but never been a big ford owner
and am a little ruff when it come to the ford diagnostic process
any help would be appreciated.

the is a spring in the steering cloumn called a clock spring it went bad on my 93 aerostar and to have the dear replace it cost about 300 buxs