This is an intermittent but confusing problem. Sometimes when I try to start my 1988 BMW 325ic, the ignition clicks for about 1/2 a second, but doesn't turn over, nothing. The battery is fine, but when this happens, nothing works (radio, headlights, etc). Later, it will start fine.
Once, the following happened: The car did the 1/2 try thing, I turned the ignition off. Got out of the car. Went into the house for other car keys. Came back into the garage, the BMW's fog lights flashed on then off and there was a car alarm-like chirp. I got in, the car started fine, but the radio code needed to be input.
Is there an alarm on my car other than the radio anti-theft device? Is the radio anti-theft device the problem, or a fuse or something else? My non-dealer mechanic suggested removing the alarm system, but he didn't say if it was a car alarm or the radio anti-theft. Is this really necessary?
Any help would be greatly appreciated!! :)

pop your hood and look for a small (probably about 4-6 inches long) loudspeaker-ish looking thing. Its probably black. If you have one then you have an aftermarket alarm. Sometimes they malfunction.

Post a pic if you can.

Thanks! Will take a look this PM.

sounds like a bad battery connection.