Sometimes car won't start, have new starter

Sometimes my car won't start; so I bought a new starter. Still doesn't start; mainly when I need to be somewhere on time. Just for kicks, we tried to jump start it once and voila, it worked. my mechanic said the fuse to the radio and cruise control was shorting out. He removed the fuse...wouldn't start twice tonight while I was running errands. He's a BMW mechanic and I think he's stumped and doesn't want to waste any more time on it. HELP! I swear it feels like there is something going on in the ignition-where the key goes in; it makes a buzzing noise too.

I have a 2001 740IL doing the same thing right now. I have ordered a ignition switch in hopes to get a fix. The car goes completely dead no power at all then I put the battey charger on it and usually within 15 minutes it will start. I have noticed that the Nav screen does act strangely sometimes.

Confirmed fix was wire bundle under left side wheel well. Wires were chaffed by metal edge of fender.

do the lights in the dash come on and the car wont start or no power no start / or crank no start.

In 3 day period it totally drains the battery. No lights at all

I have a 2001 740IL doing the same thing right now. I have ordered a ignition switch in hopes to get a fix. The car goes completely dead no power at all then I put the battey charger on it and usually within 15 minutes it will start. I have noticed that the Nav screen does act strangely sometimes.

I have a 2000 740il thought starter was out replaced ignition, nav went out, acting strangley with cd player turning off in middle of playing, now BMW states i need new nav. was your problem the same did the wire bundle repair the problem?