Originally Posted by 75 racer
I'm pretty sure the 97 Deville had the square key with VATS. If this is the case I'm pretty sure one of the tiny wires that goes into the ignition cylinder has broke. IMO the quickest way to fix this issue is to buy a new ignition cylinder, make a copy of your original ignition key without the chip in it and plug the new ignition cylinder into the steering column harness, tape your original key into the new cylinder and secure it under the dash panel and use the new copy key as your primary key. Basically this save you from tearing your steering colum apart to replace the lock cylinder and you don't need a ohm meter to figure out what resistance your key is.
I am confused, do you mean tapping your original key into the cylinder wiring?
Or did you really mean taping?
If they have a pellet in there the all you should have to do is measure the resistance of the pellet, if they do not have a multimeter they are pretty cheap for a basic one.
Get the resistance, and some resistors to match the resistance of the pellet, then at the end of each wire coming from the resistor double it back, so it looks like a closed together u, hopefully that makes sense, then just push each end into the main wiring harness spots that the ignition columns wires go into, if you do it well it will stay in there, and not fall out, that is what I did, and there was no need to cut any column wiring.
Here is an even better way to do what I am talking about, and it should not fall out, you will need to little black connector that plugs into the main wring harness though.
How to bypass the VATS system in a late model GM vehicle