Any help would be greatly appreciated... I have a 1992 Seville, 4.9L, regular (not STS), with over 150,000 miles. The car won't start when the key is turned in the ignition. I have had to "hunt" with the ignition switch for the last two years now; I turn the key and then usually have to turn the key back and forth a little to get the car to start.

But now the car won't start at all. I have tried two different ignition keys (one key is almost unused). I have tried jumping the battery. (a mechanic told me I have a dead cell, but the battery "should" be good still, since it is about 2 years old and the battery was supposed to be about a 6 or so year battery) The local mechanic spent some time and recommended that I take it to a dealer for service. They think it is the security system preventing the car from starting; they suggested that there might be something else wrong, but can't tell because the car is "locked out" by the security system. (a message comes up on the digital read-out: "Wait 3 Minutes to Start", but the car still won't start after waiting).

Thank you for any help in advance!