98 Boxster Power Drain

[Jeff_NJ]

Hi All,
I've got a problem that has me stumped. My 98 Boxster is drawing enough juice overnight to almost drain the battery.

I have already changed the battery and have gone through the fuses--I have no ideas on what to search for next without tearing the car apart.

Any suggestions?

Thanks,
Jeff

[mikefocke]

When you say you have gone through the fuses...you have removed each fuse and measured the current drain through it's socket with an amp-meter and compared that draw to the chart Porsche supplies of expected current draw? (my site on the batteries page) to see the one that exceeds the load for that period of time in the chart.

Is the battery ground cable attachment good?

Any aftermarket stuff installed?

Ignition switch?

This just suddenly happen?

Tested the alternator/voltage regulator?

What was the battery voltage when you came back from a run? Next morning?

[Wayne 962]

Right. What you need to do is to disconnect the battery and install an ammeter between the ground and the battery connection. That will tell you the amount of current drain. Then, start pulling fuses, one at at time, and check the ammeter to see which fuse causes the current drain to fall / stop. That circuit is then the one causing problems.

More on batteries here: Pelican Technical Article: Battery Disconnect Switch / Battery Buddy Installation - 986 Boxster (1997-04) - 987 Boxster (2005-08)

-Wayne

[Jeff_NJ]

Nothing aftermarket -- Stock.

It just barely held a charge the next morning--had to jump start it.

Did not check the rest--I will have to do so.

Thanks,
Jeff

[Jeff_NJ]

Ok,
I've gone through everything twice and pulled everything. Nothing on the fuses seem to stop draw on the battery. I don't really want to take the car apart to find a short.

I didn't mention a month prior to this "short", I accidentally left the top down for about an hour. It wasn't SOAKED.. I would consider it moderately damp. It worked just fine when I drove it to the garage and worked no problem for a while afterwards.

Thanks again,
Jeff

[mikefocke]

if the security computer located under the driver's seat got wet and the contacts are corroded.

I haven't seen you post the voltage while charging at 3k rpm, sitting immediately afterwords with the engine off or before you try to start it the next morning.

And while there was a battery terminal disconnected and an ammeter between the battery and the disconnected terminal, what were the milliamps reading and under what conditions was it taken? Did it remain exactly the same when each fuse was removed?