Battery light weirdness..

[BenM]

44 minutes ago, nelmo said:

Wow, that's some drain...I'm assuming you've checked courtesy lights? Maybe check the ones in the boots - put a mobile phone with the video recording in the boots and close them. Then check the video to see if the interior lights are going off when the boot closes.

Normal parasitic drain is very small and should take many days to drain a new battery....have you had any changes to the car recently? New stereo, bulbs, dash cam etc?

Left anything plugged in the 12v sockets? They stay live for some time after the key is out and I think they can stay on in some circumstances? 

No issue with courtesy lights. Original stereo, bulbs etc. Nowt plugged in to 12v socket so I don't get what any drain could be.

I have the Amazon special battery test device arriving tomorrow hopefully, so will see what that show and go from there.

Nothing worse than not trusting your car.

[iborguk]

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Edited December 22, 2023 by iborguk

[½cwt]

Basically the alternator replacement is 3 bolts, however you also need to slack off the serpentine belt.  All is accessed through the front engine cover in the cabin bulkhead (remove the carpet then about ten 10mm hex head bolts to remove.  One bolt on the alternator needs slackening and then knocking back as it has a cone washer that it pulls in when tightened.  When I did mine it just didn't want to move, but loads of Plusgas and left to soak overnight, it released first tap the next morning.  Working it out the the space was a bit tricky too.  Fir a new belt while you are in there and check all the pulleys and idlers as free running and no grumbling bearings.  There can often be a burning rubbery smell for a while after changing the belt. 

[Paul P]

My first target for parasitic drain in a car with the battery warning light on would be alternator.  
 

had this on a previous car.  Battery light on and battery draining in hours.  
 

rhe regulator / rectifier on the alternator is directly connected to battery and also controls the light.  
 

Old school car - i would charge the battery and reconnect.  Disconnect the lice lead from the alternator and check in the morning.  Access might make that a challenge on the Boxster.  

[iborguk]

6 hours ago, Paul P said:

 

rhe regulator / rectifier on the alternator is directly connected to battery and also controls the light.  
 

Old school car - i would charge the battery and reconnect.  

if it turns out to be the alternator regulator looks like that can be replaced seperately.

Example link, seem to be cheaper ones on the Bay of E/Autodoc https://frazerpart.com/products/boxster-986-987-996-997-all-models-alternator-voltage-regulator

 

Edited December 22, 2023 by iborguk

[Bike Loon]

2 hours ago, iborguk said:

if it turns out to be the alternator regulator looks like that can be replaced seperately.

Example link, seem to be cheaper ones on the Bay of E/Autodoc https://frazerpart.com/products/boxster-986-987-996-997-all-models-alternator-voltage-regulator

 

It will probably be the brushes are worn out. Changing parts on the existing one can be hit and miss and other parts may then fail shortly after on it. I would go for an replacement unit and be done with it.

[iborguk]

4 minutes ago, Bike Loon said:

It will probably be the brushes are worn out. Changing parts on the existing one can be hit and miss and other parts may then fail shortly after on it. I would go for an replacement unit and be done with it.

Agree and I would replace the whole thing, interesting to see the regulator is a separate component should someone want to go that way.

[½cwt]

3 hours ago, iborguk said:

if it turns out to be the alternator regulator looks like that can be replaced seperately.

Example link, seem to be cheaper ones on the Bay of E/Autodoc https://frazerpart.com/products/boxster-986-987-996-997-all-models-alternator-voltage-regulator

 

As long as you still have an original Porsche/Bosch alternator...

As for complete replacements, Bosch only offer reconditioned units on exchange now with 1 year.  There are other options from new with 2 or 3 year warranty.  I went for a NAPA one three years ago, 2 year warranty and £100 less than the reconditioned Bosch unit and no exchange. Fitted perfectly and still going strong.  I do intend to see if I can revive my original one at some point.

[BenM]

Thanks for the advice lads.

The guy who fitted the new battery came back and swapped it out for a better AGM

He tested the other one and is was 12.4V but just 350 amp, so said it could have been a dodgy battery.

I don't think so, as the battery light is still on with the new one, so I'm expecting the same issue.

I'll check the alternator later when the test kit is delivered.

As an aside, I'm surprised Porsche decided to fit a super heavy battery so high up on the front bulkhead. Surely it makes sense to have fitted it lower down on the boot floor or something...

[½cwt]

5 minutes ago, BenM said:

Thanks for the advice lads.

The guy who fitted the new battery came back and swapped it out for a better AGM

He tested the other one and is was 12.4V but just 350 amp, so said it could have been a dodgy battery.

I don't think so, as the battery light is still on with the new one, so I'm expecting the same issue.

I'll check the alternator later when the test kit is delivered.

As an aside, I'm surprised Porsche decided to fit a super heavy battery so high up on the front bulkhead. Surely it makes sense to have fitted it lower down on the boot floor or something...

There a big engine and gearbox under the boot....  At least they paced it centrally though.

A 986 doesn't really need an AGM battery...

[Paul P]

6 hours ago, iborguk said:

Agree and I would replace the whole thing, interesting to see the regulator is a separate component should someone want to go that way.

In this case i would  thinks it’s more likely the regulator / rectifier at fault than the spinning charging components.   It’s that part (regulator) that controls the warning light and if it is the source of the drain then that’s the component that basically either sends charge to the battery or dumps it to earth (regulator function) so if it’s faulty then it has a design that is supposed to push charge to earth and an unswitched connection to the battery.  
 

if it’s that it’s probably quite warm when it’s been doing that overnight. Might be an easy check.  
 

if it was just “battery light” and not “and a drain” I agree it’s probably the charging part and swap the whole thing. Again depends on access as to how practical it is to swap out a component rather than the whole thing.  

[Bike Loon]

1 hour ago, BenM said:

Thanks for the advice lads.

The guy who fitted the new battery came back and swapped it out for a better AGM

He tested the other one and is was 12.4V but just 350 amp, so said it could have been a dodgy battery.

I don't think so, as the battery light is still on with the new one, so I'm expecting the same issue.

I'll check the alternator later when the test kit is delivered.

As an aside, I'm surprised Porsche decided to fit a super heavy battery so high up on the front bulkhead. Surely it makes sense to have fitted it lower down on the boot floor or something...

Doesn't sound like a very good company if they do not even have a basic multimeter to check if the battery they are fitting is getting a charge.

Is it even a company? If so, that is shockingly bad

[charlieboy2608]

@BenMthis is an ideal time to locate the emergency pull cord that opens your front boot when battery faults occur.

I assume you have the micro boot releases?

Depending on year the emergency release is located in either drivers side wheel arch behind the plastic liner or passenger side-concensus here suggests early vehicles its passenger side,my 2002 MY is driver side.

[BenM]

Testing kit arrived

11.5v and 11 amp

b*ll*cks !

[nelmo]

9 hours ago, BenM said:

Testing kit arrived

11.5v and 11 amp

b*ll*cks !

11.5v when? Engine off or on?

If off, you've got a drain somewhere (and a bad one if it's killed the battery in 1 day).

If 11.5v with engine on and some revs, then dead alternator (or bad earth).

[Paul P]

not sure I get the "350 amps or 11 amps" part of this - amps is volume, volts is speed, amps you measure in line - you interrupt the flow - and "count" what goes past - you can get an estimate of "capacity" - but that's insignificant vs "volts" - but anyway - 11.5v is too low, and as above if when off then your battery is being hosed, if when running then its not charging, and its being hosed - like the light tells you -  I will revert back to the alternator - specifically the regulator for drain - but could be "the whole thing", and honestly - in my opinion , whoever is turning up and putting different batteries in and saying "its got 350 amps" is not helping, unless I am missing something that a meaningless number..... 

These batteries are what 70ah ish - thats "can do 70 amps at 12v for 1 hour" - they can probably do therefore 140 amps for 30 mins, or 280 for 15 .......... 

Battery light on when running - charging system fault, either alternator ( charging or regulator part), drive "fan" belt ( but also does waterpump, power steering and a/c ) so unlikely in this case, wiring, or perhaps seriously hosed battery - but my money is on the alternator - that part of the electronics on a 986 is old school ..... - 

 

[EXY]

On 12/21/2023 at 2:32 PM, nelmo said:

If you are seeing a charging voltage, then it's probably just an electrical gremlin that a dealer may be able to quickly fix? I've heard that changing a battery on a Porsche sometimes does screwy things like this? 

Earthing issues are not uncommon and lead to all sorts of queer anomalies. 

But I strongly suspect this isn't an Earthing issue 

On 12/22/2023 at 3:53 PM, Bike Loon said:

Doesn't sound like a very good company if they do not even have a basic multimeter to check if the battery they are fitting is getting a charge.

Is it even a company? If so, that is shockingly bad

I've heard of worse companies,  at least they came back out.

Also what was their remit, if 'please replace my battery' then it's excellent service.

If 'please come and diagnose an electrical issue with my car then replace the battery after you've cured any problems' then there's room for improvement. 

11 hours ago, Paul P said:

not sure I get the "350" part of this -  "its got 350 amps" is not helping, unless I am missing something that a meaningless number

CCA,,,,,,,,

Maybe

[BenM]

Quick update on this.

Fitted a new NAPA alternator today, in a dark cramped garage. I took the seat out yesterday when it wasn't raining, which helped access.

Connected everything back up. No battery light. 12.4v and 14.6v running. Well happy and it feels great to fix something yourself

Thanks for all the advice 🙂

[EXY]

12 hours ago, BenM said:

Quick update on this.

Fitted a new NAPA alternator today, in a dark cramped garage. I took the seat out yesterday when it wasn't raining, which helped access.

Connected everything back up. No battery light. 12.4v and 14.6v running. Well happy and it feels great to fix something yourself

Thanks for all the advice 🙂

Really glad you got it sorted, nothing like a spot of DIY for some instant gratification.

Now you're up and running again maybe it's time to change the car, we do love to offer advice on car shopping also 

[ATM]

43 minutes ago, EXY said:

Now you're up and running again maybe it's time to change the car, we do love to offer advice on car shopping also 

And divorce tips too