I have been having problems with my 99' C3500 not wanting to start sometimes. It will try to turn over and maybe start for 1 second or so then it will die. I had to google it to find out that it is an issue associated with the vehicle's Anti-theft system. I do not know which system it has in it from the factory. I have heard the term VATS, and Passlock, as well as Passlock II. Can anybody tell me which system it would have had in it from the factory in 99 and how to bypass or disable the thing. I have been having to put the key in the ignition and turn it to the "on" position and wait 10 minutes until the stupid security light quits blinking, then turn the ignition back to off, wait until I hear the fuel pump kick off, then turn it back to "on" and wait until the light disappears before I can start the truck. Bottom line is this is a HUGE PITA! I don't have time to go through this procedure every time I need to start my truck as this is a work truck and having to wait is costing me time and money. Any help would be GREATLY appreciated! Thanks!