Got my son his first car, a 1996 Caprice . Has been running great! Went to work and when he tried to start later - no start- no crank so sound but the dings, etc. Battery is string. Tried to jump - nothing. Then it dawned on me - pass fault was blinking. Cleaned off key, put in, forward 2 clicks to just before start, let it set + 10.00 minutes. No go. Sent hm to get a new key - same issue. Any ideas?? Checked fuses , all ok.
Been perfect till this afternoon. Guys showed him how to jump starter I think he said - underneath- started right up , for a few seconds, then died.

i dont have access to a drawing for that but it sounds like the vats is your issue. thats the way it worked in that time period, a starter relay disable and a fuel disable from the pcm. you can get around the start relay easy enough but the pcm wants a 50hz square wave fuel enable signal, so you can use something like this but since i have no drawings you would be on your own to come up with where it needs to go.

GM VATS Bypass Module For LS1 and LT1 GM VATS Bypass Module For LS1 and LT1 [gmvats] - $24.95 : 3rdBrakeFlasher, E-commerce web site

A blinking security light on the C/H bodies indicates that the security system is not reading any resistance across the key pellet. Usually the biggest offender is the wires on the ignition cylinder.

Assuming this is the problem, this is usually the quickest solution: How to bypass the VATS system in a late model GM vehicle

The solution posted by jwfirebird mimics the signal sent from the security module when all is well, and if the security module is to blame, that would be the better fix.

I had this condition on my car a few years ago. I did the key bypass, and have had no issues since.

If broken wires are to blame, usually the ignition tumbler needs to be replaced.

Ok, Now that my husband has admitted I have diagnosed this problem correctly,,,, Is there a way to simply disarm the VTS completely that wont take a moron all weekend to figure out ( said husband), Just need the damn thing to start. thanks.

a little more that I am reading , a few weeks ago wipers would not work, but then they do and his interior lights are very dim,. I am seeing things on here that these could actually be related! We have the ignition switch. Could someone please either send a pic or tell me in Husband friendly terms how to replace ignition switch. Thanks

you sorta have to be handy with electronics and soldering. there are two major parts the key reader and the security module. the bypass that RJ listed replaces the reader and wiring(common issue) and you have to solder in resisters in the wires that would normally go to the ign. that still leaves the module and wires to the pcm. the module i posted bypasses everything but you have to find the right wire going to the pcm and cut it and solder this module in place. you also have to bypass the start enable relay which is just taking the wires and soldering them together so its always enabled when you hit the key

We do have the ignition switch,, my sons boss got . Need directions to replace and where exactly it is located , thanks'

what you need to do is measure the resistor on the key. then find the wires coming from the ign to the security and measure them with the key turned to see if that is your problem. could have nothing to do with the ign switch. if you get the same ohms reading on the wires its the module. if not its something in the column or ign

We changed the ignition switch, not the issue. Will continue with ignition module procedure thanks. Can you get these anywhere but a dealer?

you should test things before just replacing them, thats a good way to throw away money. you should try the test i mentioned and go from there