Flat Battery- Windows Open !! - 986 Forum - The Community for Porsche Boxster & Cayman Owners

wesacosa · 01-04-2016, 02:19 AM

Hi all

Just joined here as something odd seemed to have happened on my GFs 2005 Boxster.

We came back from 2 weeks away over Christmas to find that both the drivers and passenger side window were open half way, and the rear boot was also unlocked.

Upon closer inspection the battery was totally dead. Nothing at all would work. I connected up a 12v booster to the battery and got enough power to close the windows.

The battery is a Halfords battery , 12 months old. So far it has not given any problems what so ever.

So my question is, is it possible that the windows and boot opening could be caused by a battery getting low on voltage (seems like a crazy and very unsafe situation if leaving a car for less than 2 weeks would cause it to be come open to any thief who happened to be passing) or could something have gone crazy with the electrics and it was the opening and closing of windows which killed the batterY? Any ideas would be greatly received.

Thanks
Wes

tlc356sc · 01-04-2016, 07:24 AM

Mine was dead flat one time and the AAA guy tested it. I had a charger so he told me how many hours to charge it-I did and it's been fine

for more than a year. Tom

rexcramer · 01-04-2016, 07:31 AM

I can't address the self opening. If the trunk was unlatched, it sounds plausible that the battery would be flat after the courtesy light was on for +/- 2 weeks.

pony13ca · 01-04-2016, 08:10 AM

When I bought my car, the gentlemen that owned it, hadn't started it for 3 weeks. There was just enough power to open the frunk, but no lights and she wouldn't start. However the windows were up, and the trunk was locked. Jumped the car to take it for a test drive, and the same battery is in the car working fine.

wesacosa · 01-04-2016, 11:34 PM

Thanks all

I was disappointed that battery would be flat in 2 weeks but not surprised, I can imagine this happening.

However for the windows and boot to open (they were definitely not open before we left, I can 100% guarantee that) is really shocking.

My GF spoke to her brother in law and he said he had similar issue on a Boxster he owned years ago, as the battery started to die the windows opened ! Utterly crazy

Wes

jdraupp · 01-05-2016, 03:38 AM

Quote:

Originally Posted by wesacosa

Thanks all

I was disappointed that battery would be flat in 2 weeks but not surprised, I can imagine this happening.

However for the windows and boot to open (they were definitely not open before we left, I can 100% guarantee that) is really shocking.

My GF spoke to her brother in law and he said he had similar issue on a Boxster he owned years ago, as the battery started to die the windows opened ! Utterly crazy

Wes

If you know you're leaving it for longer periods of time the best course of action is to invest in a battery maintainer.

Retroman1969 · 01-05-2016, 03:38 AM

Hmm, I don't believe that the trunk and windows open as a result of the battery going dead. I could be wrong, but.... Never seen it happen anyway. And the trunk lights are on a timer, so if you leave them open or unlatched, they turn off automatically after a time to conserve battery. (At least mine do).
The windows going half down I believe is a default mode related to the system the cocks the windows down a hair when opening the door. Sometimes my window will drop halfway down after closing the door and I have to reset it by raising the window and holding the switch for a few seconds afterward. (Probably caused by a faulty or worn switch, sensor, regulator, etc.... It's not uncommon).
These cars can kill a battery just by sitting, but not normally just after two weeks unless the battery is getting old or weak.
I'm just speculating with my limited knowledge, but it almost sounds like it suffered a power surge or glitch somewhere that triggered all of that and the same thing killed the battery.
I'd be curious to know what it was.

wesacosa · 01-05-2016, 06:52 AM

Hmm, its all very strange. I wonder if some water got in somewhere and started sending the electrical circuit a bit crazy.

I will get the battery sorted and keep an eye on it

stelan · 01-05-2016, 08:16 AM

Was the car in garage or street?
On my car if I press the unlock botton on the remote for a few seconds the windows roll down halfway, It happened before having the keys and remote in my pocket and somehow the button stays pressed

GTA_G20 · 01-05-2016, 10:02 AM

What he said^^

Sounds like when you or her walked away from the boxster, you popped the trunk and held the unlock button and rolled the windows down remotely.

The ajar trunk left the light on is what killed your battery.

Steve Tinker · 01-05-2016, 04:05 PM

Quote:

Originally Posted by GTA_G20

What he said^^
The ajar trunk left the light on is what killed your battery.

The trunk (boot) light goes off automatically after +/- 2 hours, so that's not what's flattening the battery.... but as you correctly said, maybe the OP accidently pressed the key fob button and rolled down the windows & unlocked the car too. If the car was left unlocked, it won't automatically lock for about 5 days, which (IIRC) puts more drain on the battery.

jdraupp · 01-05-2016, 04:40 PM

Yep, I lock mine in the garage because it wears down left unlocked.

wesacosa · 01-05-2016, 11:51 PM

Hmm,
the car was on the driveway, I'm pretty sure it was OK when we left the house to go on holiday but was dark and early morning so perhaps not.

Something to keep any eye on I think

Thanks everyone for the help and suggestions

Wes

wesacosa · 01-06-2016, 11:12 PM

Seems like something gone very wrong with the electrics.

I jump started the car last night. It started but as it was running all the electrics started going crazy. All of the rear lights lit up, the spoiler went up, windows went down and then the alarm horn started to sound, first intermittently then constantly. Even when I turned the engine off. Ended up having to disconnect the battery to stop all the crazy electrics.

wesacosa · 01-10-2016, 08:30 AM

well I found the problem with a bit of googling and investigation. seems there is an issue with the drain holes blocking. when this happens it floods the inside of the car and most at risk is the alarm control module under the drivers seat which controls all things which are related to opening locking and alarming car, such as windows horn lights etc. looks like a rather large bill heading our way so if you haven't already in suggest cleaning out your drain holes

stelan · 01-10-2016, 04:30 PM

Quote:

Originally Posted by wesacosa

well I found the problem with a bit of googling and investigation. seems there is an issue with the drain holes blocking. when this happens it floods the inside of the car and most at risk is the alarm control module under the drivers seat which controls all things which are related to opening locking and alarming car, such as windows horn lights etc. looks like a rather large bill heading our way so if you haven't already in suggest cleaning out your drain holes

And drill a hole under the seats so next time it rains and the back drains get clogged water can drip out of the car before flodding your electronics, I wonder if putting the whole module inside a heavy duty ziploc bag and tiying the wires tight with zip ties would make it waterproof

Richardbruce · 01-11-2016, 07:33 AM

I just finished installing the water proof immobilizer box on my 02 base. I figured the $150.00 kit was a lot less than a fried immobilizer. Kit was simple to install, well worth it!

wesacosa · 01-12-2016, 01:49 AM

yeah under seats were soaked. I assumed this was because windows were left down in rain whilst we were away but reading the forums it seems a common fault with blocked drain holes (plus I opened up the hood cover compartment and that was full of water too.

I called a Porsche specialist and I didn't even have to say the details on the phone, safe to say it seems to be a common occurrence (backed up by a search on google)

He said car wont run if the module is completely gone, but if just got a bit of water in it the car will run but electrics will behave erratically. The seat which the module is under had much less water than the other seat so that might be why it still runs.

Apparently if its completely toast then you need new keys coding to the new module so price probably doubles. If car still runs its likely you can replace module and get the key info to copy across to the new one. Will find out tomorrow if thats the case here !

Suggest everyone gets checking them drain holes and clearing out any gunk (I wish I had !)

mikomiles · 12-01-2021, 08:58 AM

My 986 windows lower when the battery goes flat. It's probably a setting that can be changed by the dealer using PIWIS like whether or not the horn beeps when you arm the alarm system. Next time I'm in for service I'll ask them to change it. It's a pretty bad "feature".