sasilverbullet

my 03 996 cabriolet keeps killing brand new batteries overnight.

Anyone have any idea where to start looking?

Thanks!

Paul 996

Do a search on here or on Renntech. I seem to recall something about a faulty ignition switch being one of the causes of the drain.

sasilverbullet

cool, will check it out...thanks!

Miller_arch

If you leave the key in the ignition it might drain the battery overnight...for me it was more like over the weekend.

Tippy

One thing I do to narrow the source down is pull fuses and look for the biggest spark.

MGS996

I spent 12 months trying to find a similar problem with my 99 Tip/Cab. The stealer charged me $900 over four visits....they could not solve the issue. I just kept my car on a charger while in the garage.

Steven C.

With the car off, disconnect the negative terminal from the battery and connect a volt meter between the battery and the cable to read the drain. You will probably need a mili-meter for small voltages. Then start pulling fuses one by one to see what is drawing the most. Very tedious but necessary.

Tonger

Bullet,

Look here for the DIY for ignition switch replacement. I think that mine had gone out for a while predating a battery replacement. The good news is that about $20 and 40 min later, it's fixed. I used eBay to find the switch and actually bought an extra for next time.

http://www.renntech.org/forums/index...ch+replacement

Good luck!

Tonger

Bijan

If you are flattening brand new batteries overnight then you are pulling a huge current (more than 1 Amp). Assuming a 80 Amp Hour battery, that is about 2 or 3 Amps over 24 hours.
As suggested, I would connect a multimeter in line with the negative terminal (remove negative terminal and connect through multimeter, set to high current reading initially), put ignition position in the state that causes the issue, possibly key out. As suggested, pull fuses one at a time until the current drops well below those observed during fault stage. Suspect the steady state current should be well below 1 Amp or 12 Watts.
If this does not reveal culprit, then I would look for non fused items, such as Ignition Swtch.
Interior lights should be preferrably off during this test, the hood light would need to be allowed for, if on.

porschedog

I went through this - turns out the WereWife had inadvertently switched on the passenger side Recaro's fan as she exited the car. Two batteries later, I heard the hum.

Bijan

porschedog better to feed power from the ignition switched supply for the Recaro's relay?

Phil G.

Takes me several months to kill 'em.

Edgy01

A few years ago I had the same problem with a Sterling (Rover, Accura thingy). I started at Sears (as they were always giving me replacement batteries (in warranty!) and finally asked them where to go to chase this down. They directed me to an automotive garage that specialized in electrical issues. Took them about 1-2 hours to chase it down. They ultimately removed a fuse that was causing the problem. What it controlled was beyond them and me. But it absolutely solved the problem. As seen above, you need to be systematic by looking for which circuit is pulling the most amps. Sometimes with small amp losses (perhaps a full battery drain down in 3-4 days) it's hard to chase with something simple like a multimeter,--but with the sort of drain you are getting (24 hours to dead) it should stick right out. Find a specialist. RARELY will a Porsche dealership be effective here. You need an electrical specialist.

Lucas,--Prince of Darkness!

judgejon

when I bought my 03 C4S it had an old Napa battery. the car sat for about 2 weeks after I got it. Then I took a long drive on a Sunday. On the following Monday the battery had drained out, and the alternator was shot and had to be replaced as well. No problems since then, but I do put the car on a CTEK/Porsche charger on weekends, or if I'm not going to be driving for a week or more.

sasilverbullet

Found that pulling the fuse for the top/windows solves the problem. Now I need to figure out what exactly is wrong in those areas.