[iamwiz82]

Girlfriend went to start the 335d this morning and popped the trunk, entered the car via comfort access, seats adjusted to her key, and then when she went to start it all hell broke loose.

Apparently all the dash lights came on, flashing, the headlights came on, the wipers came on, no start. It attempted to, she said, but then stopped. The next attempt did not try to turn over and lighting continued it's disco effect. She said eff it and was going to take the other car but then the trunk wouldn't release via the fob or the trunk release button, so her stuff is stuck in it. On top of all of this, the alarm went off while all this was going on. When it rains it pours

Now, I just installed a MusicarNW sound system and that went fine. It was done on Monday morning, drove it Saturday and Sunday with no issues. Of course my first thought is that something went wrong there, but I cannot see what could have really happened. The harnesses and such are standard, no cutting of wires.

So could this just be a bad battery? The car was built 12/2009 so it's over three years old.

[cartaa100]

did she let the glow plugs warm up and is it cold in your area?

[Quasimodem]

Maybe the stereo installation caused a drain and yes the battery may be dead. Well, that's my bet anyway.

I have a 4/2009 build 335d and the battery is still good. But I live in California, so YMMV because colder climates may be harder on batteries.

I do not have CA either, maybe that drains batteries too.

Anyway, take it to a shop that knows BMWs to check the battery because if they do end up replacing it they need to register the new battery with the car or it might blow up.

[iamwiz82]

Last night I got home and attempted a trunk pop, no dice. I threw her on my trickle charger and attempted a trunk pop again and it popped immediately, phew. I let it sit on the charger for a few hours and attempted a start and was met with a light show on the dash and such. It's definitely the battery.

[Dalbmw]

Same thing happened to my 2011 335i last week. Car wouldn't start, then the interior lights started flashing, headlights flashing, wipers came on by themselves, ect. I was pretty sure it was the battery, even though I couldn't jump it, so I had it towed to the dealer. Turns out the battery was fine, it was the starter that died and caused a short, resulting in the electrical craziness. It also fried some sort of junction box.

[iamwiz82]

So it's the battery but it's not bad, just drained. Going to keep an eye on it for now. Phew

[ctuna]

Get a Ctek3300 battery tender
If you don't already have a Intelligent Battery charger tender.
They also have a new one the 4.3
You probably discharged the battery quite a bit during the install.
I would also lock the car when done using it as it puts in sleep
mode within a minute turning off your new amps.
Otherwise the car can draw about .5 amps for 30 minutes before it
will go to sleep. (and this is for a stock car)

[Sweattdogg]

Yeah I would say the battery was drained while they did the install. Either that or something they installed is drawing current. Just because they don't cut wires doesn't mean that what they install doesn't draw power.

[iamwiz82]

It was on a tender during the install, it was something much, much sillier....

Sigh... ok it was the Cleansweep, I failed to confirm that signal sensing was set to 'on', car had the amp and CS on for almost 20 hours without running and that her in... Doh...

[Quasimodem]

Originally Posted by iamwiz82

It was on a tender during the install, it was something much, much sillier....

Sigh... ok it was the Cleansweep, I failed to confirm that signal sensing was set to 'on', car had the amp and CS on for almost 20 hours without running and that her in... Doh...

LOL Good thing I dont have a switch like that on my old AudioControl Matrix. It just has a connection for the remote signal and it turns on when it senses current.

P.S. If you didnt consult the Electronics subforum when your system was installed, you should post questions like this there -- it is a really useful forum here at e90post with a lot of knowledgeable people.