Bonnet and flat battery
Discussion
So, my 911 997 has been in the garage for longer than I thought, and the battery is pretty much flat. Bonnet won't open, so doing the yellow tweezers trick. It's pulling about 0.5 amps at 13.8v but the bonnet won't open. Not even a sound. Left the charger on for over an hour and still nothing. There's a few clicks and clacks plus flashing indicators if you use the remote fob but otherwise the car is dead. Any tricks, tips, advice? There isn't even an increase in current if you try to open the bonnet. Grrrrr.
I have a 987 Cayman which suffers from the same issue. When Porsche Assistance (also known as the RAC) came out to my car when I had this problem earlier this year, I was told that the connection in the footwell could only be used to connect another battery to allow the bonnet release to operate, not to recharge the battery.
CDR
CDR
I'm curious as to what this post is actually connected to. It's clearly not directly to the battery or it'd be pulling a lot of amps. The doner volts are good, and the parking lights will come on but only very very dimly, which suggests they aren't getting 12 volts. Is this post through a current limiter? So basically it's a slow charge point? I'm nervous leaving the car on charge all night incase the alarm suddenly bursts into life at 4am.
Had the same thing yesterday on my Cayman R.
Connect the positive from a trickle charger to the charging post within the drivers footwell fuse box, connect the negative to the door strap housing.
Press front bonnet release on the key for 3 seconds, bonnet should open.
Battery was completely flat and when connecting a trickle charger it just came up with an error message. Needed more current I suspected.
So pulled another car alongside, connected up jump leads and left engine running for an hour on the other car.
Removed jump leads and reconnected the trickle charger, started to charge.
Left overnight and now showing 3/4 charged and everything works + car starts.
Leaving on charge for another day and will then take it for a good run.
If this doesn't work, you'll probably need a new battery.
Best of luck
Connect the positive from a trickle charger to the charging post within the drivers footwell fuse box, connect the negative to the door strap housing.
Press front bonnet release on the key for 3 seconds, bonnet should open.
Battery was completely flat and when connecting a trickle charger it just came up with an error message. Needed more current I suspected.
So pulled another car alongside, connected up jump leads and left engine running for an hour on the other car.
Removed jump leads and reconnected the trickle charger, started to charge.
Left overnight and now showing 3/4 charged and everything works + car starts.
Leaving on charge for another day and will then take it for a good run.
If this doesn't work, you'll probably need a new battery.
Best of luck
I feel like I need luck at the moment.
Been in touch with SAC in Kippax who tend to know their onions. Seems that with an utterly dead battery I need to attach a bench power supply for a good few hours first just to trickle something into the battery, then attach the 'intelligent' charger for an hour or so. Should then get enough of the electronics working to recognise the key fob which will then open the bonnet.
As I say, practically nothing works at the moment apart from a few feeble clicks and clacks when to attach the doner battery.
Hopefully this will sort it.
Been in touch with SAC in Kippax who tend to know their onions. Seems that with an utterly dead battery I need to attach a bench power supply for a good few hours first just to trickle something into the battery, then attach the 'intelligent' charger for an hour or so. Should then get enough of the electronics working to recognise the key fob which will then open the bonnet.
As I say, practically nothing works at the moment apart from a few feeble clicks and clacks when to attach the doner battery.
Hopefully this will sort it.
AW10 said:
If the battery is sufficiently dead a "smart" charger won't start charging the battery. You really need to use a booster battery to open the front lid.
I'd say if in this situation with a charger available, there is no harm in the OP trying, as I have seen it work (maybe the battery was not 100% dead, but it looked that way!)The battery was so flat the key got stuck in the ignition, and you could not open the passenger door from the inside (or outside) - absolutely no response on dashboard lights, any other lighting, stereo etc, so it appeared very flat!
The charger was a Porsche branded item that plugs into the cigarette lighter socket. (Looks the same as this: https://www.amazon.co.uk/Porsche-Dual-Battery-Main... ) was left overnight, and the next day there was sufficient charge to pop the bonnet.
Attached a bench power supply this morning and it's behaving differently. Set at 13.8v it's pulling between 0.8 and 1.3A, probably because the right wing turn indicator is flashing. Only that lamp though, all the other indicators are off. Is this some sort of 'BIOS' fault code? Who knows. I'll leave it a good few hours, see what happens.
I've never seen a circuit diagram for that emergency use connection so hard to know if it just energises a subsection of the electrics in order to open the lid or if it feeds everything. But... IMHO just use it to open the front lid and then connect a battery charger. Not sure how much current it's meant to carry and for how long. Once the lid is open it seems pointless to me to risk effing up the electrics when there's an ideal way to charge the battery under the front lid.
well, I'm trying. The charging post is now only pulling 50mA which isn't anything like enough. The power supply stays at 13.8v. It's been suggested that the post might not be extended enough, or there's some other poor connection. I'll give it a try tomorrow morning.
It's annoying that what should be a relatively easy thing to sort is really snookering me at the moment.
It's annoying that what should be a relatively easy thing to sort is really snookering me at the moment.
Just a thought...if you've tried connecting a donor battery as described in the manual (and in the Rennlist link above) i.e. jump lead between battery positive terminal and fuse box and jump lead between door slam point and negative terminal...maybe the boot isn't releasing because the key fob battery is dead? In which case try it with the spare key?
Dont do what I did, I found myself in the same situation, flat battery and closed bonnet.
Then I remembered the manual release in the door jam, so I pulled it. Nothing happened, so I pulled it harder and just as it broke I realised its the manual fuel filler release. Doh !
In the end I charged the battery from the fuze box, after an hour or so I popped the bonnet and bought a trickle charger.
Then I remembered the manual release in the door jam, so I pulled it. Nothing happened, so I pulled it harder and just as it broke I realised its the manual fuel filler release. Doh !
In the end I charged the battery from the fuze box, after an hour or so I popped the bonnet and bought a trickle charger.
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