I haven't been on here lately and here I come back and post a problem. Tonight while driving home the security light came on for a short period; then back off. Then I saw it come back on for a short period, then go back off. I understand that the security system is not suppose to turn the engine off once the car has started; do I need to worry though that it might in the middle of heavy traffic.

It is the original key as far as I know; I got the car third hand; the second owner only had it a year before I got it. Could this on/off condition; I only noticed it twice, be from the key not making proper contact? Do I just need a new key made? I would have to go to the local GM and I am guessing that with the age of the car they need to order and it might be an expensive key and might not be the problem. Opinions on this please.

Should I think about just bypassing the whole security thing so I don't have to worry about future failure? If so, what are the best solutions? I have heard that a high grade wire wound pot place in line tuned to the correct resister value will work. I have the complete electrical diagram GM shop manual to go by. Or can other failures that I need to be concern with outside of the resister in the key be suspect? How to test this please.

My bonneville was doing that when I got it. I replaced the ign cylinder because the wires had were fraying and maybe broken somewhat. It lasted three yrs before it started acting up and not starting at all. I got resistors at Radio Shack and soldered them into the circuit. No more problems.

Something is surely failing, it could be the contacts inside the key cylinder, or the cylinder itself is going bad, or the key itself is so worn, its not making contact inside the key cylinder.

Use the resistor method, not the POT. I wouldn't trust a POT as far as I could throw it. If your doing the resistor trick, just use you multimeter and measure the pellet on your key using the OHM'* setting.

I am not sure about your FOB remotes but my PA security light was on and dings when I took the key out. I re-synchronized the remote by holding down the lock and unlock buttons for 15 seconds and voilla the security light is fine now.
Check your section in book and see if that is available to your car.

I don't have a FOB, there is no keyless entry on this car.

I drove it again on Black Friday, and had no problem starting the car and the security light did not come on. However, as was stated, something is probably getting ready to go out. It could be the key and cylinder are getting wrong. I lost one of the ignition key and only have one because I hated to spend the cost of that one resistor key LOL. I may do the resistor trick just so I can get a normal key made. If I lose the one I have now, it would not be so good.

https://www.gmforum.com/buick-172/no...-light-306237/

Check that page out. In random coincidence, I just responded to another post with a Security light issue, and how I managed to fix it by recalibrating the ignition sensor.

I'm not sure if it will work on a '93 LeSabre, and my '87 LeSabre doesn't have the Security system, so the actual process you have to do may differ, or perhaps not be possible at all, I don't know for sure. (Whoa, what a run-on sentence that was!) But if you CAN do it this way, it'* a dirt-cheap fix.

If it does work for you, it may only be temporary, or it might work for years. At least you can gather up the parts/cash to fix it and hopefully still be able to drive around in the meantime.