987 Dead Battery - Bonnet release and head unit questions

[Hunter]

My battery is dead and I can't get under the bonnet.

• Locking wheel nut is in the trunk, so getting behind the wheel to use the manual latch seems hopeless
• I've hooked up my charger (5A, Noco Charger Genius 5) to the fuse box terminal and it makes a loud ticking noise but does not power the release switch
  • See video of the ticking here

 

What do I do? The two local specialists don't open until Monday.

 

For extra credit: the reason the battery died appears to be my head unit. A few months ago, the head unit began to die and reboot constantly (every 20 seconds or so). This happened over a few trips, but only starting once I got up to motorway speeds. The issue "went away", retrospectively because our local motorway has been reduced to 50mph. I took the car for a drive yesterday up to 70mph and it happened again. This time, however, the boot looping seems to have continued once the engine was powered off, killing the battery. Obviously this is a huge issue if it's going to happen again.

 

Has anyone heard of this happening, and can anybody suggest a fix?

Edited December 31, 2020 by Hunter

[sevenfourate]

Been here pretty recently....

 

C-Tek charger plugged into the 12v power socket allowed me to release the frunk - and gain access to the battery - pretty quickly.

 

***Couldn’t get wheel off where it was parked in order to get to the emergency cable, and hooking a booster to the fuse-box battery terminal didn’t work for me.

 

Good luck !

[Hunter]

Thanks for the good wishes sevenfourate; I'm going to order a 12v socket for the future. It being New Years, I had to deal with whatever Halfords had, which was some low capacity jump leads... nonetheless, success.

 

Few details for anybody interested; I connected the jump leads to my partner's Picanto and, while it probably wouldn't have jumped me, it was fine to get the lid to pop.

 

Then I left it charging for 4 hours (which SHOULD have been ~25% charge, but my charger measures less), and successfully started the car. Rough start, rough idle, and a hundred and one warning lights, but things calmed down after a few minutes. Went for a 45 minute drive, parked back up and put it back on charge, still measures <25% charge, so am going to leave it overnight.

 

Still a bit worried about the head unit issue. Going to head to the local specialist and have a chat, but suspect this will be another unfortunate expense. I have the BOSE sound system, so a replacement head unit either needs the expensive adapter or a full new speaker system as I understand. I'd rather not go for a radio delete, since this is my daily.

[Beanoir™]

Have your tried doing a hard reset of the PCM? Not a soft reset from the unit itself, but by pulling the fuses.  
 

Personally though, I’d probably be looking to replace with a more modern aftermarket unit (CarPlay/android auto etc).  

[sevenfourate]

13 hours ago, Hunter said:

Thanks for the good wishes sevenfourate; I'm going to order a 12v socket for the future. It being New Years, I had to deal with whatever Halfords had, which was some low capacity jump leads... nonetheless, success.

 

Few details for anybody interested; I connected the jump leads to my partner's Picanto and, while it probably wouldn't have jumped me, it was fine to get the lid to pop.

 

Then I left it charging for 4 hours (which SHOULD have been ~25% charge, but my charger measures less), and successfully started the car. Rough start, rough idle, and a hundred and one warning lights, but things calmed down after a few minutes. Went for a 45 minute drive, parked back up and put it back on charge, still measures <25% charge, so am going to leave it overnight.

 

Still a bit worried about the head unit issue. Going to head to the local specialist and have a chat, but suspect this will be another unfortunate expense. I have the BOSE sound system, so a replacement head unit either needs the expensive adapter or a full new speaker system as I understand. I'd rather not go for a radio delete, since this is my daily.

 

Either way: glad you're sorted.

 

These 987's are renowned for parasitic draining of the electrics / charging system. Mine - with a brand new heavy-duty / uprated Bosch battery barely lasts three weeks in warmish weather. And two if its cold ! So hence sits on a C-Tek battery conditioner most of the time 

 

This may be of interest (And don't know if its applicable to switch off the LED - as this post is reference a 986)..........

 

http://986forum.com/forums/boxster-general-discussions/71827-parasitic-battery-drain-solved.html

 

 

[Hunter]

11 hours ago, Beanoir™ said:

Have your tried doing a hard reset of the PCM? Not a soft reset from the unit itself, but by pulling the fuses.  
 

Personally though, I’d probably be looking to replace with a more modern aftermarket unit (CarPlay/android auto etc).  

 

Not yet; do I need to leave the fuses out long? The local spec said the cheap option was to take out and leave out the fuse... since I have the BOSE setup.

 

I have just looked into replacing the BOSE amp as well as the head unit, because that's marginally cheaper in parts than buying the MOST adapter... but I'm not sure I could really DIY it, so labour might be nasty. If there are any techs in here, I'd appreciate a walk-through, for when I have a spare grand lying about.

 

11 hours ago, sevenfourate said:

 

Either way: glad you're sorted.

 

These 987's are renowned for parasitic draining of the electrics / charging system. Mine - with a brand new heavy-duty / uprated Bosch battery barely lasts three weeks in warmish weather. And two if its cold ! So hence sits on a C-Tek battery conditioner most of the time 

 

This may be of interest (And don't know if its applicable to switch off the LED - as this post is reference a 986)..........

 

http://986forum.com/forums/boxster-general-discussions/71827-parasitic-battery-drain-solved.html

 

 

 

I've lasted 2 weeks before on my 85Ah battery, never tested more since it's a daily. This was a full-to-zero drain overnight, so I don't think it's the normal parasitic loss (luckily?). The local specialist said no codes came up (besides low voltage ones from the full discharge), and they hadn't actually experienced this before, so want to take another look if I can get the head unit to malfunction again. Certainly glad to be back on the road.

[TTRider]

Just adding this in case it's useful to anyone else who's come to this topic, trying to get their trunk open with a flat battery.

 

In my case

- I got the driver's door open with the key

- opened the fusebox and pulled-out the terminal

- then realised my jump leads were tidily tucked in the space in the trunk with the battery and the brake reservoir so couldn't use them :o(

- so found some thick copper wire in the DIY glory cupboard, earthing cable left-over from when we'd had some wiring work done - nothing like as thick as proper jump leads but thickish multi-strand copper, wired that from the wife's car battery to the fusebox terminal and a door hinge on the Cayman as crude jump leads

- clicking noises, lights on dashboard, but the trunk release lever on the sill refused to work : urgh !

- however, after a few minutes of thinking 'what now ?', I had a go with the key fob button - and that worked, opened the trunk !

- then of course can open trunk and get at battery, could use proper jump leads battery-to-battery if I wanted to, but actually put a charger on it and left for a few hours : all then fine

[Daz]

Sound like I nightmare. 
 

I bought one of those small jumper packs about 150mm x 80mm x 15 mm its meant to be able to jump start a car but I bought and keep in one of the compartment either side of the engine just in case I need to power to open frunk. Never used yet.