I'm having no luck getting my 1996 grand prix gtp w/3.4 to start. To start with, it started acting up around a month ago. Sometimes it would not turn over at all when you turned the key on. Let it sit for a short time and try it again and it would start up. This happened several times until 3 days ago when it totally has refused to start. I thought it might be a starter problem at first. I put in a new starter and still nothing when you hit the key. The battery seems strong as far as lights and the connections are good and tight with no corrosion. Battery is approx. 6 months old. When the key is turned forward to the accessory position I notice that the security light blinks steadily all the time. Move the switch forward to start the car and nothing occurs. I have tried starting the car in park and also in nuetral with the same results. I have checked some of the fuses and they seem fine. Reading some other posts I have heard about the ignition security keys sometimes going bad. I can't test that because I have only the one ignition key. The only other thought is that my son had an after market radio installed at Best Buy around the time all this started.I would really appreciate some input as
I don't know what to check next. Thanks for any help someone can give. I have had great luck with the forums when trying to fix/diagnose problems with my Bonnevilles so I thought I would give it a try here also.

Sounds like a VATS issue to me, try your other set of keys and report back?

Sounds like VATS like Bonnememn said.

since you said you have only one key, you can try cleaning the contacts on the key with a pencil eraser, and you can dip in alcohol and insert quickly into the lock cylinder to get alcohol onto the two metal spring contacts that touch the two sides of the key.

Insert the key then and turn to on and wait. See if the VATS ever reads the key correctly and goes off after about 5 seconds.

I've had some troubles with VATS on my 98 and reading the key. I had gotten in the habit of inserting key and before it'* in completely I was rotating to On and Start. Sometimes the VATS was missing the reading and locking up on the first try. Wait 3 minutes and key is read and everything works.

The VATS should require three tries turning to crank with wrong key (won't work any of the tries) before it locks out the key and stays on for three minutes. Are you getting the 3 tries or is it locking out on the first try for 3 minutes.

I also considered the ignition switch contacts as the source of my problem, which comes and goes; I'm on the third time now. I considered putting in a new ignition switch-car has 140K miles with lots of start cycles on the switch in its lifetime.

Problem discovered in broken ignition wire. $7.00 fix.