pretty weird day for my 545.

[cac3a]

I don't know whats going today, but it hasn't been the best day for my 545.
First, the battery gave up on me. I drove to gas station, filled up and bam! it seemed like the battery didn't have enough charge to make full turn of the engine and get it going.
Anyway, jumped it and got it going. I shut off the engine at my office, came back few hours later and it started fine. So, I'm confused, but happy...until baaaam! Increased emission warning light came on. I got to where I was heading at that time, shut off the engine. Started it again after an hour, it wasn't vigorous start, but it turned and engine is running without increased emission warning light. I drove it for another 50 minutes and no light. At this point I'm like WTF is happening, but anyway I continue with my day.
Then finally on my way home, I was going to turn the head lights on and the switch is off, but pressed-in almost to the point that its flat with the dashboard. Usually is just sticking out, so its easy to grab it. I stick my fingers around and pulled it out, twisted it and lights came on. I tried to push the button back in from every possible position and it just doesn't go in. Have anyone seen anything like that?

[dwlink]

put some muscle into it. It will go back in but you actually need to push on it a little bit...

[HokieXDriver]

Low battery voltage will play havoc with BMW electronic modules and you will see all sorts of warning lights. My advice is to recharge or replace the battery. I don't think the light issue is related, however.

[cac3a]

So I got a battery replaced today, the original one was dead for sure. But, it is still undetermined whether it was time for the battery to say goodbye or something else is faulty. I have a local shop 9 (not a dealer) that works on bmw's and we checked the voltage on the alternator while on idle and the voltage kept jumping between 14v and 12v. The engine was warm and ran for about 5 minutes and that thing kept bouncing like that non stop.
The car is under CPO, does anyone know if alternator would be covered?
Also, what do you guys suggest, should I put the old battery back and take it to the dealer or leave the new battery(not oem) and take it to the dealer and tell them that other shop found the alternator misbehaving?

Last, but not least, does anyone know how much variation in voltage you have on idle?

[Bremen Ben]

On the light switch being pushed in, I had that happened to me too. One time when I entered the car my knee accidentally hit the light switch and bashed it in. It would still work but was just very difficult to turn. Took me a bit of elbow grease to pull the switch out, which I thought was broken by then. Interestingly it works normally thereafter as if nothing has happened.