Electrical drain problem! Boxster Same components as a 911 like it or not!
 

I don't understand the test, because if you connect between the positive battery, and the positive battery cable with a voltmeter you will get 12.6, and that is what I get. Also the same on my roommates car.

I am using a sears multimeter, (so it says, but I think it is far short of a multimeter) and I have tried all the settings. The meter has on it: dcv, acv, dcma, dcua, temp, and there are 5 different dials to read from..

I just can't get anywhere with this problem. I have to disconnect my battery anytime I leave the car sit for more than 3 hours. It is a strong drain.
And it will also drain like this with all fuses removed from fuse box.

Kevin

I don't think you're going to get much help from the air cooled 911 board. Maybe try the 996 forum instead. I also have a Boxster, but I can't help you, unfortunately.

connect + to - NOT + to +

Are you trying to quantify the current drain? You'll need to measure the current (in DC mA)....

..but RWebb is right insofar as "voltage"connections...


Best,

Doyle

If you're trying to find out how much your CURRENT DRAIN is ( i think that's what you're doing), then:

Hook the + terminal of the battery back up.

Unhook the - battery Cable.
Put the multimeter on DCMA
Put the + (red) lead of the meter on the battery - terminal
Put the - (black) lead of the meter on the - battery wire you have just removed.

The meter will show you how much (In milliamps) your car is pulling from the battery.

I don't know what the acceptable amount for a boxster would be . . . . .

Your method will work, in fact it is working and confirming a dead short. Keep unhooking wiring harness plugs until the voltage meter reads zero. Unplug your stereo as the memory function can fool you as it has a small drain. Unhook your alternator as it is a common cause of a drain. Make sure your doors are closed as the dome light will be a drain and cause confusion also. Rob

35ma or less is nice. they all pretty much read 12V if you do it on the + side. alarm, clock, radio memory, etc. what's important is how much the amp draw is.

Using a digital meter to test for a drain as you are doing will read 12.6 volts. I assume you are disconnecting the positive cable from the battery and reading from the battery post to the cable. The problem with a digital meter is that it has a very low internal resistance and will read 12.6 volts with almost no load from your car. What you need to do is to read a voltage drop. The safest way to do that would be to connect a test light from the battery to the cable. If it lights up there is a current flow in the car. You can test the voltage across the test light to determine the voltage drop in the light and test the amperage by connecting your meter in series with your test light. Your meter should have a 10A range and this is what you shoud use as the milliamp range is probably fuse protected and to kill a battery it is probably a signifficant load

I will only add to the confusion with my opinion. For a more objective POV, I would suggest this website that was posted by Milt a couple of days ago:

http://www.wikihow.com/Attach-a-Battery-Cut-off-Switch

There's a link on this page to measure Parasitic Current Drain.

Sherwood

[Which battery cables are you talking about??

unless you have a very nice Multimeter you will blow the fuse in it trying to meassure your drain. Average multimeters can only meassure 250ma-500ma.

Most multimeters have a 10 A or 20 A setting. And that is what you should be using. The 200mA setting is fused and the surge upon hooking up the battery can easily exceed that range. At least that is what happens on my 996 C4. I can hear several relays clicking. On cheaper models the 200mA range is fused with a 500mA fuse. On the Fluke DVMs the 400mA range is fused with a 440mA fuse. And that sucker costs 7$ if you blow it......

If your DVM doesn't have a 10A setting you might get away with initially shorting the two leads of the DVM (in Ampere setting) when hooking up the battery and then opening the short once the control units have gone through their initial setup.

Also make sure you understand the difference between measuring a current (meter in series) and measuring a voltage (meter in parallel).

A nice analogy is flow and pressure on a garden hose. If you want to measure the flow (current) you need to insert the measurement device in series between the bib and the garden hose and open the bib. If you want to measure water pressure (voltage) you need to measure between the two potentials (pressurised garden hose with no flow and ambient pressure).

Ingo

My multimeter can only meassure 250ma-500ma, and yes I already did blow the fuse in it.

I give up, I guess I will take it to someone in San Diego...or Orange County...
Maybe I dont have the tools I need.