flat batteryagain!

[pepe]

My 1985 Carrera battery keeps going flat when sitting in the garage.
I purchased ANOTHER battery ...the proper Bosh one ..I take readings every day and it goes down slowly.
I have had the altenator checked and it is ok, the electical company took a reading and the print out said change battery ..which I did .
All interior lights and boot and bonnet Bulbs taken out ..still the same
Could it be my imobiliser ?

 

[graham tompkins]

Hi Pepe, from what you say, prime suspect is the immobiliser. Is yours a Porsche one or an aftermarket one?
I had exactly the same issue on my X5, it was the bonnet switch at fault. If you isolate the switches one at a time you should find it. Engine compartment is most likely to get mucky.
regards
Graham

 

[pepe]

not sure my friend its always been in the car BUT I did get another KEY ( if that's the correct term) for it made a while back

 

[geoff Ives]

Many years ago I had the same problem with my 911 2.7S. Overnight I had no problem but give it a week and I had a flat battery. I believe that it was a problem with the window motors but I solved it by fitting a battery isolator for under £10.
It is so simple that I have fitted one to all my 'Weekend Porsches' ever since. It also adds a level of securety.

 

[graham tompkins]

Many years ago I had the same problem with my 911 2.7S. Overnight I had no problem but give it a week and I had a flat battery. I believe that it was a problem with the window motors but I solved it by fitting a battery isolator for under £10.
It is so simple that I have fitted one to all my 'Weekend Porsches' ever since. It also adds a level of securety.

Billy the Bodger fix,.......think I'd rather find out where the drain is and fix it if you have a multimeter you should be able to identify the circuit where the drain is.(put the bulbs back before you do this) If not a competent auto electrical should find it fairly quickly.
Regards
Graham

 

[pepe]

thanks will update you all next week....hope its all good

 

[911 targa]

My 3.2 had the original immobilized and the battery would go flat in a week ,fitted a Cobra and hey presto its fine
Paul

 

[Ray]

Please remember that even though the car is not being used the radio (memory) and interior clock are still being supplied. Then there is your alarm system.
I too run and a battery isolator and the cars battery is also hooked up to a management charger. But as some have said an auto electrician should be able to resolve a fault if the car has one. He will also be able to give you some professional advice on battery maintenance.

 

[supersport]

Classic causes in addition to above can be the electric window circuit, keeps the relay powered up.

 

[pepe]

Ok folks its not the immobiliser...
I am taken it to an auto electrian in the next week or so ...when I get an appointment
will keep you updated

 

[vic cohen]

FWIW i have a car same age as urs ,never had an electrical problem.......loved cherished etc etc ..............suddenly going flat overnight ,like completely,new battery proper charging and showing zero discharge when all off .........intermittent fault so whenever i checked it seemed fine !!!!

RESULT sticky passenger window operator switch.........rarely used ......always operated from drivers side ! to try just pull switch ,take wires off for a while and see what does or does nt happen

good luck

 

[vic cohen]

FWIW i have a car same age as urs ,never had an electrical problem.......loved cherished etc etc ..............suddenly going flat overnight ,like completely,new battery proper charging and showing zero discharge when all off .........intermittent fault so whenever i checked it seemed fine !!!!

RESULT sticky passenger window operator switch.........rarely used ......always operated from drivers side ! to try just pull switch ,take wires off for a while and see what does or does nt happen

good luck

 

[pepe]

Well thanks to all... its the Window operator switch...save me going to an Auto electrisian
We took out the fuses one by one and tested for shortage .. and of course it was the LAST one
Should have done what Vic said and tried the window switches...it would have been the first fuse the other way...the same fuse is for electric sunroof and heated seats which I do not have ...so must be the switch or wireing
Its the drivers switch...it will not operate the passenger window ( should do both as you know )so the fault is there just need to fix what ever the problem is
Cheers

 

[graham tompkins]

Glad you found out the culprit. Electrics on these are pretty reliable compared to many cars of the era. All part of the fun owning a classic car.
regards
Graham

 

[vic cohen]

TBH was disbelieving that the switch could kill a battery in 8 hrs

credit has to go to Steve Winter at Jaz ..........the process of illimination was long and painful

glad your sorted too