This thread is exactly one year old today, and im having the same problem, only a little different.
Last time I worked on my S10 was about 4 months ago. 4 months ago the truck started fine, no problems. So today I go to work on my truck, and my battery has died, so I went and got it charged.
Just put it in and tried to start my S10. It just cranks fine just doesn't start and the Security Light just stays "ON", no flashing, just ON.. and t has been on for the last 45 minutes.
Ive done the relearn procedure before and it works like a charm, just in this case my SECURITY light will not go out.. i don't know what to do. I just pulled out the tumbler all the contacts look good, reinstalled it and the truck has been ON for 25 minutes and the Security light is still lit??
Any thoughts on this??