I have a 97 Z-28, the wife drove it about 30 miles yesterday shut it off and a couple hours later went to start it and it would not crank, finally after about a hour it started and ran fine , checked all battery connections because I have trouble with them before all looked ok.
I got it in today and it started right up and ran fine,but I noticed that the secruity light in the instrument cluster is on , I have cycled the door locks and alarm and everything seems to be ok.
Any help would be apprecited thanks in advance.

 

Check out this link

http://shbox.com/1/pass_key.html

Could be the key or the cylinder. With the security light staying on and the car starting, it means that the car recognized a problem with the lock cylinder circuit while the engine was started and the car will restart in that condition.