Parasitic Battery Drain 1990 C4
05-10-2005, 08:40 AM
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Parasitic Battery Drain 1990 C4
Hi all,
I really need some help from you guys. My car is perfect except for ONE MAJOR PROBLEM which is driving me crazy...
I have tried for years to eliminate my battery drain problem. To save my battery going flat 2 Porsche battery replacements later since 1997, in 2001 I fitted an Optima Deep Cycle Yellow top battery + a Priority Start which has saved me from a completely flat battery ever since. The battery will go completely flat in 2-3 days from a full 12 hour charge. I have Adrian’s Book by the way
I have tried so far all theses systems with my Fluke multimetre and all seem OK
1) Checked every fuse in front compartment
2) Check every fuse in engine compartment
3) Checked Earth Strap from the gearbox
4) Checked the door switches that activate cabin lights
5) Disconnected the Front compartment light
6) Disconnected the Rear compartment light
7) Completely rewired and isolated my retrofit amp & stereo system when Off
8) Checked the blower motor was not running in the rear compartment
9 Checked the A/C control unit motor that air sensor fan
10) Porsche OEM immobilizer OK
I'm not sure what's left to check, the only thing I can think of right now would be the starter motor all the alternator/regulator although this system is charging correctly. I pulled out the retrofit alarm system many years ago and didn't replace it either.
It still pulls a couple of AMP's I'm nearly ready to give up. has anyone else had such a big problem. Any tips greatly appreciated,
Cheers, Mark - Hong Kong
I really need some help from you guys. My car is perfect except for ONE MAJOR PROBLEM which is driving me crazy...
I have tried for years to eliminate my battery drain problem. To save my battery going flat 2 Porsche battery replacements later since 1997, in 2001 I fitted an Optima Deep Cycle Yellow top battery + a Priority Start which has saved me from a completely flat battery ever since. The battery will go completely flat in 2-3 days from a full 12 hour charge. I have Adrian’s Book by the way
I have tried so far all theses systems with my Fluke multimetre and all seem OK
1) Checked every fuse in front compartment
2) Check every fuse in engine compartment
3) Checked Earth Strap from the gearbox
4) Checked the door switches that activate cabin lights
5) Disconnected the Front compartment light
6) Disconnected the Rear compartment light
7) Completely rewired and isolated my retrofit amp & stereo system when Off
8) Checked the blower motor was not running in the rear compartment
9 Checked the A/C control unit motor that air sensor fan
10) Porsche OEM immobilizer OK
I'm not sure what's left to check, the only thing I can think of right now would be the starter motor all the alternator/regulator although this system is charging correctly. I pulled out the retrofit alarm system many years ago and didn't replace it either.
It still pulls a couple of AMP's I'm nearly ready to give up. has anyone else had such a big problem. Any tips greatly appreciated,
Cheers, Mark - Hong Kong
05-10-2005, 02:57 PM
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My self and a friend have BOTH had the exact same issues with Optima batteries, both in his '87 930 & my '91 965. Last month we replaced it with an El-Cheapo from Autozone: no more issues.
Mark
Mark
05-10-2005, 03:00 PM
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My self and a friend have BOTH had the exact same issues with Optima batteries, both in his '87 930 & my '91 965. Last month we replaced it with an El-Cheapo from Autozone: no more issues.
Our battery might hold charge for 3 hours, or not, or 3 days, nor not. There was no pattern to it.
Mark
Our battery might hold charge for 3 hours, or not, or 3 days, nor not. There was no pattern to it.
Mark
05-10-2005, 03:24 PM
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Measure the Amps by putting your Fluke in series with every fuse .. one by one.
Or put your Fluke between the battery and the battery conector. Measure the Amps, and the remove each fuse one by one. Keep an eye on the Fluke. If you see the Amps goiing down, then you identified the bad electrical circuit.
Or put your Fluke between the battery and the battery conector. Measure the Amps, and the remove each fuse one by one. Keep an eye on the Fluke. If you see the Amps goiing down, then you identified the bad electrical circuit.
05-10-2005, 06:03 PM
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I have been told that a failed diode in the alternator can discharge a battery and the remaining diode pairs can continue to the charge the battery. I have not personally experienced this
but it seems like you have done a lot of looking without success. Also remember that the alternator and starter wiring circuits to battery "hot " are not fused or protected in any way which is why removing fuses will not indicate a fault in those circuits.
but it seems like you have done a lot of looking without success. Also remember that the alternator and starter wiring circuits to battery "hot " are not fused or protected in any way which is why removing fuses will not indicate a fault in those circuits.
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05-14-2005, 03:41 AM
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Fixed (I guess) Parasitic Battery Drain 1990 C4
Hi all,
Thanks fore all your input.
After all the test, and who knows what else it was the Main Negative Battery lead to ground from the battery. My alternator/regulator was not charging the battery at all below 3-4000 RPM's. I sit in traffic most of the time with the A/C going full blast so the battery was flat nearly all the time. Lucky I had the Optima (yellow top) Deep Discharge/Cycle battery otherwise, I would have killed 3-4 batteries by now if I had not installed the Priority Start, it really does work. Now at idle, the system is pumping 1-3 amps into the battery with the A/C on and headlights on High Beam. I also cleaned the connection terminal in the starter Motor amd replaced the coils, rotors & caps. The car instantly fires after now, a great improvement. I will measure the draw over the weekend to confirm these finding although its looking good.
Cheers, Mark
Thanks fore all your input.
After all the test, and who knows what else it was the Main Negative Battery lead to ground from the battery. My alternator/regulator was not charging the battery at all below 3-4000 RPM's. I sit in traffic most of the time with the A/C going full blast so the battery was flat nearly all the time. Lucky I had the Optima (yellow top) Deep Discharge/Cycle battery otherwise, I would have killed 3-4 batteries by now if I had not installed the Priority Start, it really does work. Now at idle, the system is pumping 1-3 amps into the battery with the A/C on and headlights on High Beam. I also cleaned the connection terminal in the starter Motor amd replaced the coils, rotors & caps. The car instantly fires after now, a great improvement. I will measure the draw over the weekend to confirm these finding although its looking good.
Cheers, Mark
05-14-2005, 04:33 AM
#9
So in your first post, where you said "it still pulls a couple of amps" was that something you assumed, rather than something you had measured with a multi-meter?
If you confirmed with a meter that something was using a couple of amps with ignition off, then the problem could not be your earth lead.
I'm glad you found the problem anyway.
If you confirmed with a meter that something was using a couple of amps with ignition off, then the problem could not be your earth lead.
I'm glad you found the problem anyway.
