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About 3 months ago the original battery on my '04 C4S cab died and I replaced it with a heavy duty Sears. Everything was fine till about 2 weeks ago when I went to start the car after leaving it sit for 3 days. The battery was stone dead. Sears check the batter and declared it good. Put it back in the car drove it for the day and it was fine. Two days later dead. I jumped the car drove it about 20 miles and checked I had a full charge on the battery. Disconnected the ground from it and checked the battery in 4 days. Its showed abot 11.5 volts. Took the car for a ride to be sure I had a full charge and left everything connected. Checked the battery the next day and again dead as a door nail. Before I turn the car, and my 401K over to the Porsche dealer does anyone have any ideas. I'm assuming there is a short somewhere. Thanks

Joe

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Yes, it sounds like you have a major drain.

Normally the draw on the battery with everything off should be about 40-60 ma.

If you start pulling fuses one at a time until the drain drops dramatically you can find the circuit the problem is in. Then look for the exact cause.

Or you can pay the bucks to have a shop or dealer do the same. Your choice...

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jumped the car drove it about 20 miles and checked I had a full charge on the battery. Disconnected the ground from it and checked the battery in 4 days. Its showed about 11.5 volts.

Are you sure if the battery is checked as it should? How many volt have you measured with the engine running? Since you have disconnected a fully charged battery, and the voltage drops till 11.5V on a disconnected battery, than it looks strange to me. Did i misunderstood or missed something?

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jumped the car drove it about 20 miles and checked I had a full charge on the battery. Disconnected the ground from it and checked the battery in 4 days. Its showed about 11.5 volts.

Are you sure if the battery is checked as it should? How many volt have you measured with the engine running? Since you have disconnected a fully charged battery, and the voltage drops till 11.5V on a disconnected battery, than it looks strange to me. Did i misunderstood or missed something?

Thanks RFM and Loren. RFM the 11.5V was a quick look at the gauge on the battery tester (Snap on so it is reliable). It was enough to start the car even after laying with the battery disconnected for a few days. When it was connected it drained in an overnight or about 10 hrs.

Loren I'll try the fuse diagnostic and so many fuses compared to the old cars I own. Another thought I had goes back to a problem I've seen on mid year Vettes were there is a short in the alternator that drains the battery. Can this occur with a Porsche?

Thanks to again for your help. Now if I can only get a break in the weather in northern NJ.

Joe

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