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Weird science - electrical issues after refitting battery

Arabduke

Member
Joined
6 Jan 2017
Messages
16
Electrical issues

Well not had the car long or done too many miles in it, a few 70ish mile round trips each at the weekends or so. As it appeared a wee fault occurred. I had my alternator changed as it wasn't charging the battery to high enough voltage. Starts were getting sluggish too. Garage confirmed alternator as fault and it was fitted with a new Lucas alternator.
Car was then picked up from local garage and I drove around for about 10 minutes on local A road > 50 mph. car was then parked up for a couple of days. Drive the car around 40 miles at the weekend, 1 trip 20 miles each way, fast A road. Following weekend 70 mile round trip with dual carriageway and fast A road diving. Park the car up. Go to car 1 week later and its dead, totally. No remote central locking or life. Enjoy the fuse box emergency bonnet release procedure. Check voltage on the battery and its real low, around 6v. connect up my ironically recently purchased CTEK charger which had just arrived (after reading the forum) and it does not charge the battery, keeps going into sleep mode. Borrowed neighbours booster pack and does not start car, when hooked up very, very dim bonnet light. Booster pack needs charged. Dig out my dads old, like really old 1976 12v car battery charger, hook up and check, voltage is just over 6v and needle is jumping between 0 amps and 4 amps, holding each state for a few seconds. After a while the cars alarm goes off, just as I'm under the bonnet checking voltage again. Ear hurts, a lot. No effect with the remote, put key in and it goes off. Remove key and a little later alarm goes off (bonnet and door are left open (window has dropped a fair bit also but won't go back up, no electrics!). I know its gonna snow now. This alarm thing happens a few times. Friend turns up with his 'juicy" van jump starter. This one is 600amp compared to last one at 300amp. Doesn't start the car. Though hear various clinking and noises of things coming alive. Find out the big jump starter needs charged also. Luckily he also brought jump leads, I can now daisy chain them with mine and reach for a jump start. When hooked up vehicle to vehicle electricals come alive, windows open and close, spoiler comes up and lights flash on and off. Car doesn't start, clicks on attempt to turn over. Measure voltage across battery and its up to 12.6V – hooked up to other car on. Are daisy chaining leads adding too much resistance?
We stand at chat for a few minutes pondering life.
Should have bought the RS, no the M3, no the RS4, look back at Porsche, it does look good. BLOODY START!
Another attempt - no joy. Heart sinks, wife's face says it all. Looks like more money getting spent and half the day gone. Some comment about having two big yellow boxes on kitchen bunker plugged in (booster packs). Hear the rugby from a neighbours open window, *****, I forget about that.
Friend leaves and I rehook up charger, still doing its flip flopping every few seconds. Another cup of tea doesn't help (the car or my mood). Decide to pull the battery and take inside manage to avoid the wife as its also going on the kitchen worktop. Charge up and charge bit more stable in the flip flopping, current seems to drop from 4-5amps to 3 amps, voltage is going up very slightly. I then try the CTEK again on full recond mode. Seems to initialise this time and pumps 10v when measuring across the battery. I then go and look through the cars file, it had a battery from RAC in early 2015. When I got the car in January it had a new Exide 80ah battery fitted. I monitor the CTEK and voltage is climbing to just a few millivolts under the CTEK table vs its status so looks like were now making progress. Through the rest of the day/evening the stages on the CTEK progress. Late at night reached stage 7 and voltage looks good.
Check again in the morning at its sitting at 13.6V hooked at final stage.

After work that day I fit the battery, and there's life. Start the car and it kicks in first time. Voltage before hooking up and on load and on idle all look good. HOWEVER, not all is well. Window is dropped doesn't want to go back up, console is dead, radio/screen after initial flash up goes off chrono clock makes a sweep and error message after error message on dash. Spoiler also pops up. CL not working, fans not working. Lights don't go on apart from rear right. Strange. I leave for a while at idle and let her warm up checking voltage across battery.
I decide to venture out and go for a wee roundy in the estate about ½ mile out and 3 point turn it back. PASM and dash still error messaging. Dad is round and suggests it may be a faulty relay or needs hooked up to a dealer computer (is he on commission? I got a fright at Aberdeen's dealer hourly rate whn I enquired about getting a new key flashed, how can they charge so much!). I check a few fuses and the all are OK.
Park up and switch off. Restart and find that the radio/sat nav screen comes on, windows will work and lights will come on (headlights) but they all go back off again fairly quickly and do not respond. If I switch off again and on and if I'm quick enough I can raise the window and lower the spoiler and open the front bonnet before this 'sleep mode" kicks in. some things link the rear lights, brake lights and horn still work. Others like the hazards, seats or spoiler wont. I just have no idea why this is happening. Car starts fine, electrics start but after a very short while literally a couple of seconds or so mist systems seem to power down. The PCM screen doesn't get past the Porsche splash screen before the console powers down.

Anyone any ideas? Any help would be most appreciated.

Cheers.
 
Hi, sorry to read about whats going on inside your car, must be only to frustrating!! Not being to much help, but am sure someone will be on here soon who may have had this expetiance and know how to solve this!! But in the mean time id go to a priest to carry out an exorcism, may help ! :D goodluck thou!!


j
 
Electrical issues are the work of Satan and are not to be messed with but it could well be the earth strap which connects to the starter motor.

It's a common problem and the engine has to be dropped to change it I believe.

If the car is under a warranty then give the seller a call, if not then take it to a professional.

Good luck.
 
the bit that annoys me, is that the specialists told you that it was the alternator, a lot of these specialists guess, ive had a lot of costly guessing lately, dressed up as knowledge, sometimes they cant be bothered to do a tricky job, and go for an easy money maker that can easily be excused.

I am tired to the core of specialists.

I hope it works out for you,i know your pain. :thumb:
 
I don't know specifically about the 997. But my thoughts are something like:

There is a stray load somewhere which is discharging your battery much faster than it should do. This will kill batteries stone dead in no time at all which would explain the multiple replacement batteries. The one you have now is probably not going to last if it has been completely flattened. You need to find the drain and fix it, then get a new battery. If you are methodical they can be pretty easy to track down, you just need a multimeter and some time. Plenty of information online on how to do it.

The boosters might struggle to start the car if the battery was completely dead as the battery would be taking a huge amount of current and if the pack is not tip-top it might not be able to supply enough for what the battery will take as well as enough to start the car without the voltage dropping too much.

I know that earth cables can be a problem. I would say that in this case that is less likely to be an issue as it wouldn't explain the battery being flattened too quickly. It would explain a car not starting, but the battery would measure OK in those circumstances.

When trying to start the car was it always done at 12v or were 24v packs used to try to start it? If 24v was used this might have caused other issues. For 12v systems can get in a mess just from having power on and off with various voltages. If that is the case I would suggest an orderly power removal for 30 minutes and then a reconnect.

MC
 
Hi Cheers for the replies.

I've checked the fuse in the main foot well bay and all appear to be good, think I'll try an checked the voltage across them but suspect that I wont see anything.

12v was used to start the car.

When I get home tonight going to try and disconnect and reconnect, I suspect there's perhaps a power relay or module that's faulty or gone between the battery and the foot well fuse box. will need to try and trace that.

trying to find a good auto electrician around Montrose now, know of any good ones?

cheers
 
Well got home sharp from work and found battery dead. getting a dab hand at the emergency unlock procedure!
Battery was 3.54V plugged in situ and 6.6V on the bench so appears there's some draw on it in the car, what I do not know. So recharging the battery and going to call an auto electrician .. hopeful not going to cost.... :whiteflag: :sad:
 
Arabduke said:
Well got home sharp from work and found battery dead. getting a dab hand at the emergency unlock procedure!
Battery was 3.54V plugged in situ and 6.6V on the bench so appears there's some draw on it in the car, what I do not know. So recharging the battery and going to call an auto electrician .. hopeful not going to cost.... :whiteflag: :sad:

For the price of a cheap multimeter and some patience you can have a good go yourself. I am happy to talk you through it.

Either way, you will need a new battery.

MC
 
I expect its battery / discharge related but one other thing it might be or as well as a battery fault is the power distributor pin corroded .. post here about it ..

http://911uk.com/viewtopic.php?t=118716&highlight=

It causes wierd electrical fault and what seems like a flat battery .. only to find it starts later without jumping or charging .

Reguards windows .. press the window button till its closed , release then press and hold for 5 secs .. that will teach it its top position .

Steering angle / psm / pasm faults after a battery disconnect are nornal , drive over 6 mph and they will go .

For any discharge / drain faults then the sterio system is the usual place , moveing onto trackers etc etc , need to know the measured discharge rate after 1 hour .
 
Arabduke said:
Hi MC!

I have a multi meter and I'd be grateful for any assistance. :)

I will post info here in the hope it is useful to others.
The basic principle is that you need to measure the current when the car is turned off and asleep. You need to connect one lead of the multimeter to the chassis and the other to the negative terminal of the battery, in such a way that when you disconnect the battery the multimeter is still connected. You then need to fool the car in to thinking that the drivers door is closed and the bonnet is closed, you will need to look up how to do that as I have never done it on a 911. Lock the car and wait 30 minutes. Set the multimeter to a 2A range, disconnect the negative terminal and look at the current. You should be seeing 50mA or less. If you are seeing more then start pulling fuses one by one and seeing what effect they have on the current. When you fond which circuit is responsible it gives you a big clue as to where the fault it. Also search for common faults for current drain on this model. PM me if you need more info.

MC
 
:agree:

Push the catch closed on the bonnet lid lock and the door lock catch with a screwdriver .

If locking then double press with the key fob to turn off interior monitoring .

DONT pull any fuse thats listed as alarm .

30 - 60 mins for an accurate reading .. you will get a workable reading after 15 - 20 mins but it will be higher ( a little ) than after 1 hour.

If its a pulsed reading then that does indicate certain things as does a discharge of 4 amps +

Most car meters only have millamps or 10 amps .. set to 10 amps if thats the case .. thats all mine has anyways .
 
Ok cheers guys, just have the probes for the multimeter so will look to get croc clips. So I take it the idea is to keep multimeter in series with batter in situ and remove car earth using multimeter in line, sounds simple enough will just need to figure out how to hook this up and keep the bonnet closed.


so the battery is presumed gone then, I emailed the garage I got the car from ( in January this year) as they said it was a new battery fitted, it did look new and clean as looking on the web the battery is under 3 yr guarantee. Hopefully the will change it if not I'll need to look to replace.

current make is EXIDE 110 80 Ah 700 CCA measuring L315mm x W175mm x H175mm

looking on web it appears the standard one is H278 x W175mm x H190mm 096 type.

are Exide a good enough brand? really not familiar with car battery brands though by name I'm looking at the Bosch S5010 (5yr guarantee) similar to current Exide in size and power or the Bosch 096AGM 6yr and smaller though 190mm height.
the Exide 110TE Exide also seems to be good too.

these fellas seem to be cheapest:
http://www.justcarbatteries.co.uk/s5010-bosch-silver-110-battery.html
http://www.justcarbatteries.co.uk/exide-110te-ea852-car-battery.html
http://www.justcarbatteries.co.uk/s6008-s6001-bosch-silver-096agm-battery.html


cheers.
 
Bonnet stays open .. it must ..

Look at the lock , there is a small lever to the left , you use screwdriver to push it closed .. simulate what the bar on the bonnet does in other words , you will then have the bonnet open but the lock in the closed position .

Same with the door , screwdriver into the lock will close the door catch.

You dont have to lock the car with the fob .. you can just wait for the systems to shut down but it will take longer and not be in the normal alarmed state .

Batterys .. i let others decide as i just fit what im given :)
 
Agh, no Kelly Le Brock :nooo:
 

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