I have a 1992 Bonneville SE (200+K miles) that has a strange issue. It has been stalling and restarting after sitting. This began a few weeks ago, I haven't been driving it for a couple of weeks, been too busy working to look at it much. I noticed that it will drain the battery just sitting there for a short time. It will stall while driving and then restart but only after it sits and only if it has not drained the battery. I had Autozone check the battery, they said it was fine. It has 14V coming from the alternator. I am not sure where to begin. I think I may have a short to ground somewhere, especially since it drains the battery sitting there. Sometimes it kills the battery in a matter of a half hour. It is dead now. I can jump it and it starts no problem, and charges the battery. But them it will drain the battery, sometimes rapidly, other times not. I can get behind the wheel and make it to Canada, or 2 miles away, toss of the dice. Any ideas on how/where to even begin? It does have a few weird electrical anomalies, the trunk switch sticks some and I have the electric door lock and windows problem where some work some do not. I did clean the ground busses, visually checked the main battery cables. Thanks for any and all help.

My Bonnie did the same thing it was a bad Crank sensor. I got it replaced and that did solve my problem. Good luck with yours.

Yeah, but did it drain the battery? This is what is throwing me off the crank sensor.

If its your battery then I would check the following 3 things first the inside of your terminals where the jacket meets the ring for your battery they get filled with corrosion mine were I cleaned them up with coke and a wire brush the lube with grease, second the ground block on your engine where your battery connects to on the front passengers side bottom front of the engine or the ground wire on your alternator. Best of luck.

I think possibly it is some of that. I get 14.3 volts between the alternator and battery and across both battery terminals when it is just started. Now, it is still running strong at idle but I get 13.5 volts. Also, the alternator gauge is reading around 12 volts (by eye) but nowhere near the usual 14 volts it used to. I am thinking maybe the alternator is good but I have a bad ground somewhere. I will check all the wiring again and have a closer look at the battery terminals/wires. My question, is it possible for a bad battery/alternator/ground connection to make the car run fine and then stall and start later and sometimes just flat out kill the battery?

The car is now at running temp and stalling everytime I start it unless I give it gas. It has 12.2 volts at the battery, 13.5 or so at the alternator.

Are you close to an Autozone or O'Reilly'*? If so, take your alternator and battery in to be tested. Its free, and helps to eliminate the obvious.

How is the quality of the idle before it stalls?
When was the last tune up?
Have you cleaned the throttle body recently?
Do you know of any vacuum leaks?

I had a problem like this in a van that I had. New battery, checked voltage yet it kept going dead. Auto Zone replaced the battery a second time. Replaced regulator (Was a Dodge). In the end, it turned out to be the alternator. With the motor running and nothing else on, it showed 14+ volts. With the headlight, and heater going it would drop to under 12v and while the van would run, as soon as I shut it off it was done. Like 2KG4U said, get the alternator tested.