Anthony DiBernardo

The battery keeps on losing its charge, the keyless entry no longer works and the car battery has been replaced, twice, one of them recently. I was told that there is a 3 amp draw on the battery and possibly the rear defroster accounts for 1 1/2 draw. The alternator has also been replaced. It used to take about 5 days to drain the battery but it now happens overnight. I've taken it to several shops with no results. The nearest dealer is over 100 miles away and I'd like to get this resolved without going to a dealer. Any input you may have will be appreciated. Thanks.

Macster

you'd hook up meter to measure current flow or parasitic load from the battery then start pulling fuses until you pull the fuse the causes the largest drop in current flow from the battery.

If you need current draws for various subsystems ask and I'll dig it up and post so you can tell what's "normal". This info not specific to Boxster but just some general numbers, but still valid I think.

Then once you have a suspect circuit start tracing the wiring -- a wiring diagram helps -- looking for shorts, bare wires, etc. If you can disconnect the various items from the circuit and see if the trouble lies in the device/system at the end of the circuit vs. somewhere in the "middle".

In your investigation keep sharp eye out for rodent sign. Rodent damage is always a possibility with electrical problems.

These kinds of problems are some of the hardest to trouble shoot cause the wiring harness is usually buried behind/underneath all other hardware, etc.

I've seen vehicles with all their internals (seats, carpets, dash, etc.) out to expose the wiring harness for ease (?) in tracing short or other suspected wiring harness problem.

Sincerely,

Macster.

Ryan C

The most common battery power consumer that I have seen take out batteries is a broken Lojack system. If your car is preowned you may have one and not even know it. Everyone that I've ever pulled out of a boxster or 996 is under the passenger side airbag. Usually found installed with duct tape and/or wood screws. They're usually wired into a dome light circuit, so if pulling that fuse shows an issue present in that ciruit you may want to start there.

Under the passenger side dash is a sheet of foam that's held in place by 2 plastic fasteners. Unscrew those remove foam and you'll see and A/C duct. Remove it and if you have a Lojack that's where it'll be, warpped with duct tape around the long metal knee gaurd. It looks like to small black boxes both the same size and one of them is clearly a battery and will be wired to the car.

4sound

Unplug the connector that goes to the Ign. switch...then see if the battery is dead the next day. Of course there are other things that can cause a draw. I have seen so many issues caused by a bad Ign. switch. If it is bad, replace it with 99634701707.